Device for Heart Repair

ABSTRACT

An anchor ( 9 ) for implantation in body tissue ( 26 ) to hold a line ( 14 ) comprises a number of hooks ( 62 ) for engagement with the body tissue ( 26 ) and having a folded position and an unfolded position, wherein the anchor ( 9 ) is made of an elastic material such that it can be elastically deformed into the folded position by application of a constraining force, and will return to the unfolded position when no constraining force is applied, and wherein the hooks ( 62 ) are formed with openings ( 64, 66 ) along their length, wherein the openings ( 64, 66 ) in the hooks ( 62 ) comprise slits extending along some or all of the length of the hooks ( 62 ).

The present invention relates to various parts of a device forimplanting an artificial chordae line in order to repair a heart valve,as well as to related methods. This disclosure also includes an anchorfor implantation within body tissue, which may be used for heart repair.

The chordae tendineae are cord-like tendons that connect the papillarymuscles to the tricuspid valve and the mitral valve in the heart. Thevalves consist of leaflets that open and close with the beating of theheart in order to control blood flow and blood pressure within theheart.

Mitral valve disease presents an important challenge to cardiac surgeonsand cardiologists. Mitral regurgitation has become the leadingpathophysiological condition of the mitral valve in the developed world.One of the most important causes of regurgitation is prolapse of one ofthe mitral leaflets. The pathological abnormality that requires repairis rupture or other degenerative changes of the chords, leaflet or otherrelated structures. When the chord(s) remain intact, the mitral leafletsopen and close synchronously and in a fashion that prevents leakage ofthe valve. The normal chords can rupture acutely causing acutedecompensation, in the form of, heart failure. This usually results inan emergency condition requiring rapid intervention. Damage to thechord(s) can also occur more slowly including rupturing or elongationdue to degenerative processes, causing the mitral valve to develop leaksor regurgitation.

Surgical repair of the mitral valve has become relatively standardized,using resection of the prolapsed leaflet and/or implantation of new,artificial chordae lines to control leaflet motion. In addition a mitralring is frequently placed to shrink the size of the mitral valveannulus. Surgical replacement of ruptured or elongated chords is highlyeffective in eliminating or minimizing mitral valve regurgitation. Theprocedure is presently performed with open heart surgery techniques.This requires use of cardiopulmonary bypass and arresting of the heart.This surgical approach, although working well, is a highly invasiveprocedure which can cause serious complications, long hospital stays andsubstantial expense. Consequently a less invasive approach would bepreferable.

Insertion of mitral leaflet chords has been done using a minimallyinvasive surgical approach entering the heart through its apex. Thetechnique, was developed by the company Neochord Inc. and is described,for example, in WO 2012/167120, but still requires a surgical incisionand the chords do not get inserted in the papillary muscles where theynormally should be fixed.

WO 2008/101113 describes another example of a system for repair of theheart, including implantation of artificial chordae lines. In thedescribed method an anchor can be attached to the papillary muscle andis coupled to the leaflet of the mitral valve by an artificial chordaeline, a suture and a clip. The clip allows for adjustment of the lengthof the artificial chordae line. A complex multi-stage process isrequired to implant the papillary anchor and the suture and join themtogether. The papillary anchor is formed of a memory metal such asnitinol and has a ‘flowered’ shape with sharp ‘petals’ for hooking theanchor to body tissue. The flowered shape is flattened into a tube shapeand held in a tube that is passed into the heart. The tube and anchorare then pressed against the papillary muscle and the anchor is pushedout of the tube so that the petals pierce the muscle and fold outwardthrough the muscle to provide a secure coupling of the anchor to themuscle tissue. In a subsequent surgical procedure, an artificial chordaeline may be attached to the anchor. Then in a further step, the sutureis attached to the leaflet and this suture is joined to the chord by theclip. The suture is attached to the leaflet by locating a vacuum portnear to the leaflet and pulling it into the vacuum port where it can bepierced.

It will be appreciated that this technique, whilst avoiding open heartsurgery, still requires a sequence of relatively complex steps. Thenumber of steps required increases the risk. Furthermore, the complexityof the device means that parts implanted within the body are at risk ofcoming loose and injuring the patient by embolization. In particular,the clip could come loose from the anchors. It is also thought that theuse of a suture with an additional clip, as proposed, may noteffectively repair the heart valve since it will not closely simulate anatural chord.

In an earlier patent application, WO2016/042022, the present applicantdisclosed a catheter device for implanting an artificial chordae line torepair a heart valve. The catheter device of WO2016/042022 includes amechanical gripper device for grasping the leaflet of the heart valve,with a leaflet anchor housed in the gripper. The leaflet anchor can beformed from a flexible material, such as nitinol, with a grapple hookshape in an unfolded configuration, and being able to deform elasticallyinto the folded configuration, for example when constrained within aleaflet anchor channel in the gripper device. The hooks are straightenedout when the leaflet anchor is in the folded configuration. When theleaflet is grasped by the gripper device then the leaflet anchor can bepushed out of the gripper to drive the hooks though the leaflet whilstthey return elastically to the unfolded configuration, thereby securingthe leaflet anchor in the leaflet.

The device described in WO2016/042022 also uses a papillary anchor witha broadly similar arrangement of foldable hooks. The papillary anchor isheld within a tube of the catheter device in a folded configuration andcan be pushed out of the tube with the hooks being driven through thepapillary muscle whilst they return elastically to the unfoldedconfiguration, thereby securing the papillary anchor to the muscle. Thepapillary anchor includes a locking ring acting as a locking mechanismfor clamping an artificial chordae line when no force is applied. Thelocking ring maybe elastically deformed to release the line from thelocking mechanism for adjustment of the length of the chordae line.

Whilst the device of WO2016/042022 provided a significant advance inthis field it has been found that further refinement of the design maybe advantageous. The present disclosure relates to new features buildingon the design of the device disclosed in WO2016/042022 in variousrespects.

In accordance with the present invention an anchor as discussed in theseventh aspect, a method of use of an anchor as discussed in theeleventh aspect and a method of manufacture of an anchor as discussed inthe fifteenth aspect are herein provided.

Viewed from a first aspect the invention provides a catheter device forrepair of the heart by implanting an artificial chordae line, thecatheter device comprising: a leaflet anchor for placement in a leafletof a heart valve, wherein the leaflet anchor is arranged to be coupledto the artificial chordae line; and a leaflet anchor deploymentmechanism for deploying the leaflet anchor to attach it to the leafletof the heart, wherein the leaflet anchor deployment mechanism comprisesa mechanical gripper device for grasping the leaflet of the heart valve,wherein the gripper device comprises a leaflet anchor tube for housingthe leaflet anchor in a folded configuration; the gripper device andleaflet anchor being arranged such that when, in use, the gripper devicegrasps the leaflet, the leaflet anchor can be pushed out of the leafletanchor tube to pierce the leaflet and form the leaflet anchor into anunfolded configuration so that hooked formations of the leaflet anchorcan, in use, secure the leaflet anchor in the leaflet; wherein themechanical gripper device includes a first gripper arm rotatably coupledto a main body of the catheter device so that the first gripper arm canrotate relative to the catheter device to move an outer end of the firstgripper arm away from the main body of the catheter device and a secondgripper arm rotatably and/or slideably coupled to the main body of thecatheter device so that the second gripper arm can rotate and/or sliderelative to the main body of the catheter device to move an outer end ofthe second gripper arm away from the main body of the catheter device;and wherein the first and second gripper arms are arranged so that theycan move to come into contact with one another at a point spaced apartfrom the main body of the catheter device.

This arrangement can provide various advantages. For example, in thearrangement where the second gripper arm is rotatably coupled to themain body of the catheter device and/or where the second gripper arm canreact to a sufficiently high force from the first gripper arm, then theuse of two gripper arms allows for the leaflet to be gripped between thetwo arms at a point spaced apart from the main body, rather than onlyenabling the leaflet to be gripped between a single gripper arm and themain body, which is the arrangement described in WO2016/042022. The useof two gripper arms in this way can additionally or alternatively helpstabilise a flailed leaflet, which is a leaflet segment withoutfunctioning chorda, that may flail into the atrium and be hard to catchwith prior art devices. For example, the leaflet tends to move upwardswhich can make it difficult to catch the leaflet using a single gripperarm alone. Thus, in this regard, the second gripper arm may beconsidered as being a ‘leaflet motion suppressor’, as it may help tostabilise the flailing motion of the leaflet during a cardiac cycle. Theuse of a second gripper arm may also allow for a more horizontalgripping/contact surface (i.e. more perpendicular to the main body ofthe catheter device), which is beneficial both in terms of constraintson orientation of the main body, which is typically inserted from abovethe leaflet, and also has further advantages in relation to exampleembodiments in which the implantation of the leaflet anchor is carriedout using the same device that implants a papillary anchor. Inparticular, the use of two gripper arms with a more perpendiculargripping location can facilitate the use of a device for performing theprocedure of implanting both a leaflet anchor and a papillary anchorwhilst the device remains in one place. It will be appreciated that thegripper arms may not necessarily be rigid structures, but may beflexible as required to achieve their desired operation.

In some examples, the use of two gripper arms allows for motion of theleaflet to be restrained between the two gripper arms at a point spacedapart from the main body. Thus, at (and near) the point(s) where thefirst gripper arm and the second gripper arm can contact one anotherthen when the leaflet is present they will engage with the leaflet andrestrict its movement. The leaflet tends to move upwards which can makeit difficult to catch the leaflet using a single gripper arm alone.Thus, in this regard, the second gripper arm may be considered as beinga ‘leaflet motion suppressor’, as it may help to stabilise the flailingmotion of the leaflet during a cardiac cycle. Thus in thisimplementation, the second gripper arm may be slidably moved away fromthe main body of the catheter device to contact the top of the leaflet.The catheter device may be moved downwards such that the first gripperarm may then be rotatably moved away from the main body of the catheterdevice without contacting the leaflet or the second gripper arm, beforebeing rotated back towards it. As the first gripper arm rotates backinto the main body it then contacts the second gripper arm, which mayfor example be a flexible arm, restraining the leaflet between the two.The contact made by the first gripper arm against the second gripper armmay in this case be a slidable contact, allowing the first gripper armto rotate back towards the main body whilst maintaining restraint of theleaflet. The first gripper arm then grasps the leaflet between itselfand the main body of the catheter device. Hence as the first gripper armis withdrawn back to grip the leaflet between the first gripper arm andthe main body, as similarly described for the single gripper arm inWO2016/042022, the second gripper arm restrains the leaflet and preventsthe leaflet from slipping out and thus the presence of the secondgripper arm ensures the grasping of the leaflet in the first gripperarm. The use of a second gripper arm will also allow for a morehorizontal gripping surface (i.e. more perpendicular to the main body ofthe catheter device), which is beneficial both in terms of constraintson orientation of the main body, which is typically inserted from abovethe leaflet, and also has further advantages in relation to exampleembodiments in which the implantation of the leaflet anchor is carriedout using the same device that implants a papillary anchor. Inparticular, the use of two gripper arms with a more perpendicularcontact location can facilitate the use of a device for performing theprocedure of implanting both a leaflet anchor and a papillary anchorwhilst the device remains in one place. It will be appreciated that thegripper arms may not necessarily be rigid structures, but may beflexible as required to achieve their desired operation.

The improved design may also allow large parts of the device to beproduced from an elastic metal such as nitinol or stainless steel, andthis in turn can allow for a production method that is reproducible andinexpensive. Alternatively, large parts of the device may be producedfrom a composite material, with choice parts formed from an elasticmaterial such as nitinol or stainless steel as appropriate. Thecomposite materials may comprise, for example, glass reinforced PEEK orcarbon reinforced PEEK (CRF PEEK). Composite materials may have theadvantage of improved imaging from ultrasound to allow monitoring duringany procedure the catheter device is used for. Whilst compositematerials may be not be as visible in x-ray imaging, radioactive markersor opaque contrast markers may be strategically located on the device toprovide for such imaging. Composite materials may also be used forinjection moulding of the components of the catheter device as required.

It will be appreciated that the leaflet anchor deployment mechanism ofthis aspect, as well as providing its own advantages, may also combinesynergistically with the catheter devices of the aspects describedbelow. Thus, it may be used to deploy the leaflet anchor in the deviceof the second aspect, for example with the leaflet anchor deploymentmechanism placed in the proximal part of the two-part housing section.Alternatively or additionally it may be combined with the use of anejector unit as disclosed in relation to the sixth aspect.

Capturing a leaflet with flail can be challenging, as it can move both“up” and “down” during a heartbeat. The gripper device of this aspect isequipped with an additional gripper arm to address this issue. The twogripper arms can both move relative to the main body of the catheterdevice. In some examples, the first gripper arm acts to enclose thesecond gripper arm, such that the first gripper arm must be rotated by acertain amount away from the main body of the catheter device before thesecond gripper arm can be freely rotated and/or slid within its entirerange of movement. It may be that the second gripper arm can only bemoved relative to the main body of the catheter device once the firstgripper arm is opened to a certain degree.

The leaflet anchor tube may be housed within either the first gripperarm or the second gripper arm. The leaflet anchor is deployed by pushingit out of an opening at the end of the leaflet anchor tube, which is atthe end of the respective gripper arm. In the example embodiments theleaflet anchor tube is within the first gripper arm, which may alsoenclose the second gripper arm as discussed above.

The two gripper arms may be operated individually to allow forindependent movement. Alternatively, they may be linked in order thatthey move simultaneously similar to a “tweezers” mechanism. The use oftwo gripper arms can allow the upper gripper arm, which may be thesecond gripper arm, to make a “roof” for the leaflet, reducing themovement, and making the grasping easier especially when the leaflet isa complete flail. Another benefit is that the grasping action is morehorizontal rather than vertical, i.e. more perpendicular to the mainbody of the catheter device than parallel to it.

In one example the first gripper arm may be arranged to be opened byrotation away from the main body, through 45 degrees or more, andpreferably to an obtuse angle. The second gripper arm may be arranged tobe enclosed by the first gripper arm when the first gripper arm isclosed, and may be able to swing and/or slide outward from within themain body of the catheter device once the first gripper arm is open.Where the second gripper arm rotates then it may rotate with an oppositedirection of rotation to the first gripper arm and may be arranged sothat the rotation brings the end of the second gripper arm into a pathof movement of the end of the first gripper arm. A centre of rotationfor the first gripper arm may be spaced apart along the length of themain body of the catheter device compared to a centre of rotation of thesecond gripper arm. It should be noted that the centre of rotation maynot be fixed as there may be some deformation of the device during therotation process, for example the first gripper arm may rotate bybending of a flexible section of material, which can lead to movement inthe centre of rotation depending on the degree of bending. In caseswhere the second gripper arm slides then it may slide to move its endoutward from the main body of the catheter device and into the path ofmovement of the end of the first gripper arm.

The gripper arm(s) may be moved by pulling one or more wire(s), whichmay be connected to lever arms joined to the gripper arm(s). With thesecond gripper arm open (i,e, rotated or slid outward from the mainbody) with its end spaced apart from the main body, for example with thesecond gripper arm extending at an angle of between 45-90 degrees fromthe main body, then the first gripper arm may be rotated in the closingdirection toward the end of the second gripper arm, such that the firstgripper arm moves to contact part of the second gripper arm.

In some examples the gripper device may capture the leaflet, and/orrestrain its movement, by engagement (contact) of the two gripper arms,which may be done by rotation of one or both arms. The second gripperarm may also be individually moved during the gripping action. The twogripper arms may move in order to engage a gripping surface of thesecond gripping arm with a gripping surface of the first gripper arm.

The gripper device may capture the leaflet by first restraining itbetween a contact point between the second gripper arm and the firstgripper arm. The first gripper arm may then be rotated closed, i.e.towards the main body of the catheter device, such that the restrainedleaflet is successfully grasped by the first gripper arm. The secondgripper arm may remain fixedly in place during motion of the firstgripper arm.

For the gripper arm that houses the leaflet anchor tube, which may bethe first gripper arm, the gripping surface may be a gripping platformlocated around the opening of the leaflet anchor tube. Whilst theleaflet is gripped between the two gripper arms or a gripper arm and themain body of the catheter device, the leaflet anchor is placed, forexample using any technique discussed above and then the gripping deviceis opened, for example by rotation of the first gripper arm away fromthe second gripper arm and/or the main body of the catheter device.Where the device of this aspect is combined with the device of the sixthaspect and hence an ejector unit is present, then the connection of theleaflet may be tested after the gripping device is opened to ensureproper placement of the leaflet anchor in the leaflet prior to releaseof the leaflet anchor from the ejector unit.

The second gripping arm may be actuated with two wires, allowing thephysician to move it in two rotating or sliding directions to aid in thegrasping process.

The second gripper arm, i.e. the leaflet motion suppressor, may be aflexible member and/or may comprise a wire. The wire may be formed of anelastic material such that it may be contained, housed, stored and/orsheathed within a lumen of the main body of the catheter device when notin use. The elastic material may be nitinol or stainless steel, forexample. This advantageously gives a user of the device the decision ofwhether or not the use of the second gripper arm is desired duringplacement of the leaflet anchor.

The leaflet motion suppressor comprising an elastic wire may be in anelastically deformed state when stored within the lumen. However, whenthe leaflet motion suppressor is moved away from the main body of thecatheter device the leaflet motion suppressor may return to anundeformed state. The leaflet motion suppressor may be slid out of thelumen to move its end away from the main body of the catheter device.

The leaflet motion suppressor may comprise a number of shapes and/orarrangements capable of suppressing flail of the leaflet, to ensureengagement of the leaflet between the first gripper arm and the secondgripper arm, when the leaflet motion suppressor is in its undeformedstate.

In one example the second gripper arm may be a looped nitinol wire thatis pushed out of the proximal end of the device, by pushing the twoproximal wire ends toward the distal end of the device, a looped wireextends out of the proximal end of the gripper housing. The loop in thewire may advantageously stabilise the leaflet motion suppressor as itengages the leaflet. The loop of wire may encompass a large surface areawhich assists with engagement of the leaflet.

The loop of wire may also prevent the leaflet motion suppressor frombeing withdrawn completely into the catheter device. That is, the loopof wire may engage with a feature of the lumen such as a pin, such thata distal end of the wire is always outside and/or flush with a main bodyof the catheter device. Thus for the leaflet motion suppressorcomprising a wire, a portion of the wire and/or an end of the wire maybe located outside of/flush to an outer surface of the proximal part ofthe main body of the catheter device.

In another example, the second gripper arm may be an open-ended and/orloose wire, i.e. a wire wherein at least one of the ends is locatedoutside the main body of the catheter device when in the undeformedstate. The wire being open-ended and not forming a loop may help prevententanglement of the leaflet in the leaflet motion suppressor. In thisarrangement, the leaflet motion suppressor may comprise a number ofbends and/or curves parallel to the plane of the leaflet, whichadvantageously increases the surface area of engagement between theleaflet motion suppressor and the leaflet. To prevent the leaflet motionsuppressor from being completely withdrawn into the catheter device, thewire may comprise a wire stopper at its end, the wire stopper being afeature such that the wire stopper is wider and/or larger than thelumen.

When the leaflet motion suppressor comprises a wire with at least oneend of the wire configured to be outside the main body of the catheterdevice, the leaflet motion suppressor may undesirably pierce and/ordamage the leaflet or surrounding tissue as the second gripper arm isslid out of and/or moved away from the main body of the catheter device.With the aim of preventing this disadvantageous effect, the bends and/orcurves of the wire may be formed such that the end of the wire isconfigured to point away from the leaflet. For example, the end of thewire may curve away from a surface of the leaflet, or may point in adirection opposite to that which the second gripper arm is to be moved.Additionally and/or alternatively, the end of the wire may comprise asoft tip to decrease the chance of puncturing the surrounding tissue.

In one example, the undeformed shape of the leaflet may comprise aspiral, the spiral forming a large engagement surface between theleaflet and the second gripper arm. The spiral may also be formed suchthat the end of the wire located outside the main body of the catheterdevice is at the centre of the spiral. Advantageously, this decreasesthe likelihood that the end of the wire pierces and/or damages thesurrounding tissue as the end of the wire is less exposed.

The lumen in which the leaflet motion suppressor is stored may comprisea channel, path and/or conduit running along a length of the catheterdevice parallel to a main axis of the catheter. However, where the lumenmeets the mechanical gripper device the lumen may angle towards an outersurface of the main body of the catheter device such that the leafletmotion suppressor may slide out of the lumen to engage the leaflet. Thelumen may be angled such that the leaflet motion suppressor leaves thelumen perpendicular to a surface of the main body of the catheterdevice.

The wire component of the leaflet motion suppressor may be anoff-the-shelf wire, such as a guide wire, readily available for use incardiac interventions. Accordingly, an operator of the catheter devicecan then choose a wire that they find appropriate for suppressing motionof the leaflet during an operation. In other words, different wires ofan identical predefined size may be implemented with different stiffnessand/or tip structure (i.e. bends, curves and/or loops) as desired. Forexample, if a first wire did not function as desired, a second wirehaving similar or different characteristics may be used. As such, theleaflet motion suppressor may not be stored within the lumen of thecatheter device permanently, but may be selected from a storage deviceand inserted into a port of the catheter device during a particularlychallenging procedure. This approach has the further advantage that itmay use wire components for which regulatory approval has already beengranted, and/or wire components that the user is familiar with fromother types of cardiac interventions.

The first gripper arm may be actuated with a single wire or withmultiple wires. Advantages can be obtained if a hinge mechanism for thefirst gripper arm is formed integrally with the material of the mainbody and rotates away from the main body by elastic deformation of thatmaterial. The first gripper arm as well as the hinge mechanism may beformed integrally with the material of the main body. Alternatively, thefirst gripper arm may include a separately formed arm section, such as amilled piece or a laser cut piece, with the separate arm section beingattached to a hinge mechanism of the main body, for example by gluing orwelding.

In a slightly different arrangement the second gripper arm may beattached to the base (somewhere close to the rotational “axis”) of thefirst gripper arm. This second gripper arm may be an elastic materialsuch as nitinol. In a default configuration the second gripper arm mayfollow the gripping surface (inner surface) of the first gripper armwith a slight pressure towards the gripping surface of the first gripperarm, with the pressure being induced by tension in the material of thesecond gripper arm. The arrangement can be compared to a “reversed”tweezer, where a force is needed to open it. The reversed tweezerfollows the movement of the first gripper arm unless there is a forcethat pulls it open, the force could for example be in form of a pullwire, or wedge placed in between the first and second gripper arm.

In some examples, the main body of the catheter device may be formedfrom an elastic metal such as nitinol with a hinge being provided by anelastic joint formed in the elastic metal. In that case a single wirecan be used to elastically deform the first gripper arm by bending anelastic joint with the main body to rotate the end of the first gripperarm away from the main body, with the first gripper arm returningelastically to its at rest position once no force is applied to thewire. An advantage of this is that the elastic force of the firstgripper arm can hold it in place against the second gripper arm when theforce is released from the wire, without the need for a separate wire tobe pulled to keep the grip on the leaflet secure. A second wire mayhowever be implemented as a backup if it may be needed.

In other examples, the main body of the catheter device may be formedfrom a composite material, such as carbon or glass reinforced PEEK. Thefirst gripper arm may then be joined to the main body of the catheterdevice using a pin joint, the pin forming the axis of rotation of thefirst gripper arm. Similarly, when the second gripper arm comprises asheet of elastic metal, the rotatable element of the arm may be formedby another pin joint located on the surface of the main body of thecatheter device. The pin joint mentioned herein may be a revolute jointor a hinge joint, i.e. comprising intermeshing features with a pin orcylindrical member joining said members, the pin forming the axis ofrotation for the joint. The motion of the second gripper arm may then becontrolled by one or more pullwires, as described above. When the secondgripper arm comprises a single wire as described above, the lumen may beformed through the composite material to allow passage of the leafletmotion suppressor in and out of the catheter device.

Alternatively or in addition the first gripper arm can be heat set in a“more than closed” configuration. This would allow the first gripper armto grasp tissue towards the main body of the device as well as towardsthe second gripper arm.

To form both the first gripper arm and the hinge integrally with themain body of the catheter then the main body of the catheter maycomprise an outer tube, with the first gripper arm being formed as anarticulated section of the outer tube. Several forms of slits and/orpatterns can be formed in the tubing in order to provide a weakenedhinge section allowing for bending without plastic deformation of thefirst gripper arm.

In alternative arrangements a hinged gripper arm may be used. In thatcase the first gripper arm may be milled, actuation in that case couldbe done with a spring for closing, and wire for opening, or vice versa,or with two wires (one for opening and one for closing). A pulley cut inthe device can be used to redirect the pulling force from the pull wire.

One or both gripping surface(s) may be arranged to hold the leaflet withfriction. For example the gripping surface(s) may use a material with ahigh coefficient of friction and/or the gripping surface(s) may have atexture or surface profile for increasing friction, such as a ridged orsaw-toothed profile. The end of the leaflet anchor tube typically opensinto one of the gripping surfaces. The leaflet anchor tube may take theform of a generally cylindrical channel sized to be slightly larger thanthe leaflet anchor in its folded configuration.

The leaflet anchor may be formed from an elastic material and to bearranged so that it assumes the unfolded configuration when no force isapplied, and to be able to deform elastically into the foldedconfiguration, for example when constrained within the leaflet anchortube. Further possible features of the leaflet anchor are discussed atvarious points below.

It is advantageous if the leaflet anchor can be placed into the leafletfrom beneath, i.e. from the side where the papillary muscle is located.To facilitate the preferred placement of the leaflet anchor frombeneath, the catheter device may be arranged so that the open end of theleaflet anchor tube is at a proximal end of the gripper device (the‘upper’ end when in the heart in the above defined orientation) and theleaflet anchor can be pushed out of the channel moving from the distalend of the catheter device toward the proximal end. Thus, the end of thefirst gripper arm may also have the end of the leaflet anchor tube, andthis may be arranged to direct the leaflet anchor in a directionextending toward the proximal end of the catheter device. In someembodiments the catheter device includes a U-shaped rod for deploymentof the leaflet anchor, as discussed further below.

In some examples the second gripper arm can be cut out of the main bodyof the catheter device in a similar way to as the first gripper arm, forexample cut from a piece of the main body at an opposite side of themain body to the first gripper arm. This second gripper arm could havecut features in its base, allowing for a tight bend being pulled out ofthe device, and may also be heat formed for increased stiffness.

In examples using a mechanical hinge for the first gripper arm thecatheter device main body could be made of an elastic metal such asnitinol while the first gripper arm itself is milled from stainlesssteel otherwise formed separately. Alternatively, the main body may bemilled with the gripper arm cut from elastic metal, or the entire devicecould be milled or made by additive manufacturing.

The leaflet anchor tube can be heat treated with a flattened section onits inner end that extends past the first gripper arm's “centre” ofrotation. This can act as a lever for pulling the first gripper armopen.

The second gripper arm may be cut from sheet metal, such as nitinol, andplaced within the main body of the catheter device in an elasticallydeformed state. This deformation may be purely to allow the arm to takea smaller profile for insertion into the main body, so that it willexpand into a non-deformed state once it is within the main body.Alternatively, some elastic deformation may remain once the secondgripper arm is within the main body, for example, so that it will retainitself in place via elastic forces and/or so that it may automaticallydeploy by unfolding elastically when the first gripper arm is opened.The second gripper arm may be formed with heat setting with for examplea light curve or a convex curve to improve stiffness and or provide agripping surface. Wave or barbed edges may be provided in order toenhance the gripping strength of the gripping device. In addition, oralternatively slits can be placed on the surface of the second gripperarm to provide different flexing properties. In some examples a hingemechanism for the second gripper arm is formed in the main device by theuse of two holes, with pins formed in the second gripper arm that fitinto the holes. This may be assembled by inserting the second gripperarm with elastic deformation as discussed above, and by allowing thesecond gripper arm to fully or partially unfold into a position wherethe pins engage with the holes to make the hinge. Wires can be attachedto the second gripper arm to move it up and down, or it could be springloaded one way, and pulled the other way.

When the two armed gripper of this aspect is combined with the secondaspect and its flexible joint, then in one example the two-part housingsection of the second aspect is made from a single tubing section cut toa required shape, with the first gripper arm being provided in theproximal part of the two-part housing section, which forms the main bodyof the catheter device, and with the first gripper arm advantageouslybeing cut from the same tubing section. In this way it becomes possibleto create many features of the catheter device from a single tubingsection, such as from laser cut nitinol. Alternatively the two-parthousing section of the second aspect is made from two parts coupled witha hinge, as discussed above, and in this case the catheter device may beformed from a combination of materials, perhaps including compositematerials.

Viewed from a second aspect the invention provides a catheter device forimplanting a leaflet anchor and a papillary anchor into the heart aspart of a procedure for implanting an artificial chordae line thatextends between the leaflet anchor and the papillary anchor, thecatheter device comprising:

a two-part housing section extending from a distal end of the catheterdevice along the length of the catheter device toward the proximal endof the catheter device, the two-part housing section being arranged tobe placed between the papillary muscle and a leaflet of the heart duringuse of the catheter device, and the two-part housing section comprisinga distal part at the distal end of the catheter device and a proximalpart located on the proximal side of the distal part;

a leaflet anchor deployment mechanism at the proximal part of thehousing section for deploying a leaflet anchor for attachment to theleaflet of the heart;

a papillary anchor deployment mechanism at the distal part of thehousing section for deployment of a papillary anchor for attachment tothe papillary muscle, wherein the papillary anchor deployment mechanismis arranged for deployment of the papillary anchor by moving it outwardin the distal direction relative to the distal part; and

a flexible joint located between the proximal part and the distal partof the two-part housing section, wherein the flexible joint allows acentreline of the distal part to be angled relative to a centreline ofthe proximal part.

The device of this aspect provides a new method to insert the papillaryanchor that may allow the physician to implant the leaflet and papillaryanchors without the need to move the device after first placing theleaflet anchor, or after locating the device ready to place the leafletanchor/grasp the leaflet (with the papillary anchor being placed firstin the latter situation). In contrast to the device described inWO2016/042022 the catheter does not necessarily need to be moved to adifferent orientation or position within the heart before the papillaryanchor is placed. Instead the flexible joint may allow for the distalpart to be angled toward the papillary muscle area while the remainderof the catheter device is not moving. The flexibility of the joint, canalso allow for the distal end of the distal part to push more evenlyagainst the papillary muscle, i.e. to ensure that it presses against thebody tissue more evenly across the whole cross-section of the distalend. In turn this ensures effective implantation of the papillaryanchor, since it can engage with the body tissue around the wholecross-section.

This device hence reduces the risk of entanglement as well as minimisingthe time needed for the implanting procedure. In WO2016/042022 a methodto place the anchor is described but the design of the papillary anchordeployment mechanism and its housing needs greater care to ensure thatall of the anchor pins were well engaged with the body tissue. It shouldbe noted here that in this document the term “pins” is usedinterchangeably with the term “hooks” and the same elements of theanchor is described in each case.

Optionally, the flexible joint may also be extendable. Thus, there maybe a flexible and extendable joint between the proximal part and thedistal part of the two-part housing section. The flexible and extendablejoint may allow the distal part to be moved away from the proximal partvia extension of the joint to thereby extend the distal end of thecatheter device further into the heart. In this way the device can beextended to move the distal part of the housing section along with thepapillary anchor in a direction toward the papillary muscle area whilethe remainder of the catheter device is not moving. The resilience ofthe flexible (and extendable) joint can act to avoid excessive force onthe body tissue, reducing the risk of trauma during implantation, aswell as aiding in ensuring an even pressing force with the extending andflexing mechanisms working in combination.

The papillary anchor may consist of a number of pins that are arrangedto form hooks in the body tissue as the anchor moves out of the distalpart of the housing section into a deployed configuration. In someexamples a papillary anchor of similar design to that of WO2016/042022could be used. In other examples the papillary anchor may have furtherfeatures as discussed below, such as slits along the pins. The proposeddevice of the second aspect might also be used with other types ofanchors that need to be placed at a distance, such as a screw anchor ora barbed anchor.

As explained above, by adding a flexible joint between the two parts ofthe housing section a more reliable deployment and lower chance ofentanglement can be achieved. The flexibility of the joint also helpsthe device travel through bends in the catheter as it is split into twoshorter straight parts that can flex relative to one another, ratherthan being one long rigid section. The flexible joint allows acentreline of the distal part to be angled relative to a centreline ofthe proximal part, and these centrelines may be aligned with acentreline of the catheter when the device is at rest. It will beappreciated that the device will have a prismatic form, typicallycylindrical, and the centrelines may hence be along the centre of thecross-section of the prism. During use of the device the centreline ofthe proximal part of the housing section may remain aligned with acentreline of adjacent parts of the catheter that support the housingsection, whereas the centreline of the distal part may be angleddifferently.

The optional feature of an extendable joint also allows the distal partto be moved away from the proximal part to thereby extend the distal endof the catheter device further into the body/heart, and thus it has atelescopic effect that changes the overall length of the two-parthousing section. Where a flexible and extendable joint is used this mayhave two separate mechanisms to provide the required flexibility andextendibility. Thus, there may be a mechanism arranged for bendingbetween the two parts, and a separate mechanism for extension via someform of telescopic effect. The telescopic effect might in this case beprovided by a sliding sleeve arrangement, by foldable or hingedstructures, and/or by elastically collapsible structures. In otherexamples, including the example embodiment illustrated herein, theflexible and extendable joint may have a single “flextendable” partproviding both the flexing and extending functions. This may for examplebe a foldable and/or elastically collapsible structure, such as abellows arrangement (as with flextendable drinking straws) or astructure with one or more collapsible coil and/or wave shapes, such ascoil springs or a set of parallel meandering paths.

The two-part housing section may be formed from two tubular sections inany suitable material, i.e. a medically appropriate material. Stainlesssteel or nitinol may be used. In the alternative, composite materialssuch as carbon-fibre or glass-fibre reinforced PEEK may be used. Thecatheter device may be formed via a combination of such materials withthe materials for different parts of the device being selected dependenton the required characteristics of those parts. A material that allowsUltrasound to pass through and at the same time have sufficient strengthis preferred, Carbon reinforced PEEK meets these demands well, and wouldalso allow Injection moulding of the components which lowersmanufacturing cost. Fibre reinforced plastic are normally not visible onX-ray, so strategically placed radiopaque markers in all components maybe used to determine device component(s) position and orientation onX-ray relative to each other, as complementary information to ultrasoundimaging.

In some example embodiments a flextendable element is formed byproviding collapsible forms into the walls of a tube made of a flexibleand elastic material, such as nitinol or another shape memory metal.Laser cutting may be used to provide the required forms. The extendableand flexible joint can be cut with any suitable pattern to achieve therequired functionality. For example, it may be formed as a regular (e.g.helical) spring. The extendable and flexible joint may be cut withasymmetry to achieve desired flex patterns and asymmetric forces duringcontact of the distal end with the wall of the heart. A thin walledsilicone element is a possible alternative to a tube cut intocollapsible forms. For example, a thin walled silicone tube that can bestretched many times its original length. In that case the silicon tubepart may be connected to the gripper section and papillary anchorsection via suitable support brackets.

The flexible and extendable joint can be extended during the procedurefor insertion of the papillary anchor, as discussed further below. Itcan also be extended independently or be under compressive-tension priorto insertion and then be released (making the device longer, pushing theheart wall).

It is also possible to use the flexible and extendable featureindividually, i.e. not in direct conjunction with the placement of theleaflet anchor. Thus, the procedure could be split into two stages, onefor attaching sutures to the leaflet, and one for placing the papillaryanchor. When the steps are done individually there may be advantagesfrom using a telescopic tube to provide all or a part of the extendablefunction, as the device can be made shorter with that approach.

The joint may have mechanical shielding internally and/or externally toprevent wires, chordaes or tissue from getting pinched. This may be inform of a flexible membrane that stretches with the extendable joint,for example a thin sleeve that sits outside the joint. The membrane maybe a silicone membrane which is fixed onto the outside of the unit aboveand below the joint. For example it may be fixed with adhesive.Alternatively a flexible layer of silicone (or other flexible material)could be over moulded onto the flexible joint to reduce pinch riskduring movement of the joint. Fabric covering techniques similar to whatis done to cover oesophageal stents or stent grafts may be applied tothe joint.

In some examples using a flexible and extendable joint the joint may becovered by a tube section that extends all the way to the distal end ofthe catheter device when the flexible and extendable joint iscompressed. This may for example be a thin walled nitinol tube. Thisallows the extendable joint to be completely covered during its entiretravelling length. The covering tube may reduce the amount of flex inthe device, therefore a further flexible section may be added just abovewhere the covering tube is attached to the device, for example bycutting a pattern. The covering tube may be welded or glued onto thedevice body.

The delivery handles used by the operator to control the device may becoupled in such a way that the artificial chordae line(s) are extendedwhen the lower section of the device is extended, in order to hold thechordae in proper tension independent on how much the lower section ofthe device is extended. Additionally or alternatively, a constanttension device such as a constant force spring may be disposed in thedelivery handles to achieve proper tensioning of the chordae and thusremove any slack in the chordae line(s). The removal of slack from thechordae by keeping the line(s) in tension may prevent entanglement ofthe chordae between itself and any other components in the device.

The flexible and extendable joint can be formed in a default extended,compressed or somewhere in-between “spring configuration”, to allowdifferent means for movement/functionality. It could also be heat setpartly stretched, which can allow for reduced use of material.

The leaflet anchor and/or the leaflet anchor deployment mechanism may besimilar to that of WO2016/042022. Alternatively or additionally theleaflet anchor and the leaflet anchor deployment mechanism may havefeatures as discussed below.

The papillary anchor is housed within the distal part of the housingsection before its deployment. The papillary anchor may have a similarcross-section as the distal part of the housing section. For example,both may have a tubular form when the anchor is held in the distal part.As noted above the anchor may have a folded and an unfoldedconfiguration allowing pins of the anchor to form into hooks within thebody tissue during deployment of the papillary anchor. The papillaryanchor deployment mechanism may take a similar form to that ofWO2016/042022, and/or it may have further or alternative features asdiscussed below.

In one example the papillary anchor deployment mechanism includes afirst wire or rod for pushing the papillary anchor in the distaldirection relative to the distal part of the two-part housing section.There may additionally be a second wire or rod for releasing thepapillary anchor from the papillary anchor deployment mechanism in orderto disengage the papillary anchor from the catheter device after it isimplanted in the body tissue, i.e. the tissue of the papillary muscleand/or tissue adjacent to the papillary muscle.

The papillary anchor may have a chordae line attached to it, and mayinclude a locking mechanism, such as a locking ring as in WO2016/042022and as discussed below, the locking mechanism being for clamping thechordae line when no force is applied to the locking mechanism. Thelocking ring may be able to be elastically deformed to release the linefrom the locking mechanism for adjustment of the length of the chordaeline. The papillary anchor deployment mechanism may include a lockingring holder for holding the locking ring in its elastically deformedposition, with the papillary anchor deployment mechanism being arrangedto selectively withdraw the locking ring holder from the locking ring sothat the chordae line can be locked in place after deployment of thepapillary anchor and after any required adjustment of the length of thechordae line. This locking ring holder may have a Z-shape as discussedbelow.

The flexible joint may include a hinge element, for example with thedistal part of the two-part housing section coupled to the proximal partvia a pivoting mechanism or via an elastically deformable element. Forexample, the two parts of the housing section may be composite or metalparts coupled together by the hinge element.

In some examples the flexible joint is controllable via one or morewires, such as nitinol or stainless steel wires. There may be a wireallowing for control of the angle of the flexible joint by pushingand/or pulling. There may be three wires that are distributed in asupport section in the housing section and/or attached to the flexiblejoint, for example to achieve a complex movement, such as where thejoint is also extendable. These wires may be arranged so that when oneor more wires is pushed or pulled then this will control movement of thedistal part of the housing section. For example they might change theangle or extension of a flexible and extendable joint. The three wiresmay be arranged to be used by pushing or releasing in order to extendthe device to retrieve a placed papillary anchor while still holding theleaflet in the gripper. The wires may also be arranged to be used toangle the distal part to be more perpendicular to the heart wall, for amore optimal placement of the papillary anchor. In some examples thehinge element is controllable via one or more hinge pullwires.

The hinge pullwire(s) may be of the form of the one or more wiresdescribed above. The hinge pullwire(s) configured to control the hingeelement may be arranged to sit inside and/or pass through the front ofthe catheter device (wherein ‘front’ refers to the side of the catheterdevice shaft where the leaflet anchor deployment mechanism may belocated). The hinge pullwire(s) configured to control the hinge elementmay also be arranged such that they are radially offset from a centralaxis of the catheter device, i.e. such that they are proximate a wall ofthe catheter device rather than a central axis of the catheter device.

When the hinge pullwire(s) configured to control the hinge element arearranged as described above, the hinge pullwire(s) may act as adeflection wire, i.e. the hinge pullwire(s) may be configured such thatwhen the distal part of the two-part housing section is angled relativeto the proximal part of the two-part housing section through the use ofthe hinge pullwire(s), the hinge pullwire(s) may deflect a device shaftof the catheter device in the same direction that the hinge element ofthe flexible joint is angled. This may have the effect of increasing theforce acting on the wall of the heart during deployment of the papillaryanchor from the catheter device. The actuation of the hinge element andthe deflection of the device shaft may be sequential or simultaneousduring operation of the hinge pullwire. For example, during operation ofthe hinge pullwire the device shaft may deflect at the same time thehinge element bends, or during the operation of the pullwire the hingeelement may bend first and the device shaft may deflect second.Additionally, when the hinge pullwire(s) is actuated the device shaft ofthe catheter device may be steered in a target direction. Thisbeneficially assists in ensuring that the distal part of the two-parthousing section is perpendicular to a target wall of the heart duringpapillary anchor deployment.

In some examples the flexible (and optionally extendable) joint is cutwith laser from an elastic tube (for example a nitinol tube), that alsoacts as the structural component of the entire catheter device, suchthat the tube also forms the distal part and proximal part of thetwo-part housing section. Different types of patterns can be applied tothe tube edge towards the tissue to achieve different friction and/orpotential “hooking” to keep the device stable during implantation, oneexample is a wave pattern edge or a flange with increased surfacetowards the tissue. To avoid pinching of the new chordae a sheath tocover the suture inside the joint can be implemented, wherein the suturesheath can be retracted/opened once the placement of the anchor isconfirmed.

An example of the use of the catheter device of the second aspect mayinclude the following steps: (1) the device is first placed in nearproximity to final placement; (2) the flexible joint is angled to movethe distal part toward the papillary muscle and the wires/rods alongwith the papillary anchor within the distal part move with it, forexample due to friction between the papillary anchor (or a papillaryanchor push tube) and the internal surface of the distal part of thehousing section; (3) the distal end of the distal part meets the bodytissue, and as force is applied the counterforce from the body tissueeventually surpasses the forces holding the papillary anchor in place,at this point tissue is pushed flat below the base of the device givinga maximal chance of placing all pins correctly in tissue, and force canbe applied to the anchor so that the ends of the pins then move beyondthe distal end of the distal part to meet the body tissue, this may bedone via additional force on the anchor from rods or wires, oradvantageously it may be done through a pre-tension on the anchor thatis held by friction with the distal part until the forces from the bodytissue on the distal part changes the balance of forces with thefriction sufficiently so that the papillary anchor ejects (similar to apaper stapler); (4) the papillary anchor pins fold out and form into thehook shape of the unconstrained papillary anchor to thereby engage withthe body tissue, at which point the connection can be pull tested byoperator, and/or visually confirmed on x-ray and/or ultrasound; (5) ifthe connection is not satisfactory, the papillary anchor can be pulledback into the device and re-placed to attempt an improved coupling ofthe anchor with the body tissue. The same device may also implant theleaflet anchor, which can be done after implantation of the papillaryanchor, or optionally prior to implantation of the papillary anchor.During the implantation of the papillary anchor the leaflet anchordeployment mechanism may be used to grip the leaflet, with or withoutdeployment of the leaflet anchor.

It will be understood that the operation of the catheter device of thesecond aspect to implant the papillary anchor may be compared to a paperstapler, since force on the device end (when being pushed) will drivethe papillary anchor out of the end and into the material adjacent theend similar to a stapler. In a typical example, once the device is inposition and the leaflet is secured (for example in a gripper as inWO2016/042022, or as discussed below) then the papillary anchor can beplaced, if placement of papillary anchor is approved, the leaflet anchorcan be placed, if not then the leaflet might be detached and papillaryanchor retrieved to be placed again. The flexible joint in the centre ofthe device also improves movement through the catheter, especiallythrough arcs, as it can more easily go through curves as two shortercomponents connected with a flexible joint.

In some examples the actuation of the leaflet anchor can be connected tothe papillary anchor deployment, meaning that the leaflet and papillaryanchor may be at least partly deployed at the same time. This can makethe procedure easier and/or faster.

Viewed from a third aspect the invention provides an anchor systemcomprising an anchor for implantation in body tissue to hold a line, theanchor comprising a number of hooks for engagement with the body tissueand having a folded configuration and an unfolded configuration, whereinthe anchor is made of an elastic material such that it can beelastically deformed into the folded configuration by application of aconstraining force, and will return to the unfolded configuration whenno constraining force is applied, wherein the end of each of the hookscomprises a tip, and wherein the tips are formed to curve towards acentral axis of the anchor when the anchor is in the foldedconfiguration.

As it will be appreciated, for the hooks to engage with the body tissuethe tip of each hook must be able to pierce the target body tissue. Theend of the tip is therefore generally sharp and/or pointed. By requiringthat the tips of the hooks are curved towards a central axis of theanchor when the anchor is in the folded configuration, i.e. that thevery ends of the tips are spaced inwardly of some other part of thehooks, then the ends of the tips advantageously do not contact an innersurface of a container device providing the constraining force toelastically deform the anchor. For example, if the container deviceconstraining the anchor to be in the folded configuration was a tubulardevice, the tips would be curved away from the inner surface of thetubular device such that the ends of the tips do not contact the innersurface. Instead, a smoother portion of the hooks will lie tangential tothe inner surface and be the contact point between the hooks of theanchor and the container device. Thus, in the folded configuration theoutermost portions of the anchor may be portions of the hooks spacedapart from the ends of the tips of the hooks, with the tip ends beinglocated inward of those outermost portions and extending toward thecentral axis of the anchor. The tips of each of the hooks therefore arenot able to scratch and/or scrape the inner walls of the containerdevice constraining the anchor. This prevents damage to the containerdevice, as well as avoiding the risk of shavings of the container tubematerial from being created, which may be undesirably deposited in theregion of the target body tissue. Although a small deposition ofmaterial may seem negligible, the shavings may cause haemorrhagingand/or may cause an embolism that could result in a stroke.

The anchor may be made of an elastic metal, for example, nitinol orstainless steel, while the container device may be made of a compositematerial, such as a material comprising a matrix with reinforcing fibresor particles, for example, carbon reinforced (CRF) PEEK. It will beappreciated that the metal of the anchor could easily damage thecomposite material of the container device.

The anchor system may include the container device along with theanchor. Thus, the anchor system may comprise a container device holdingthe anchor in the folded configuration, wherein the tips of the anchorcurve inward away from the container device. The container device mayprovide a constraint around an outer circumference of the foldedconfiguration of the anchor and it may be a tubular container device asdiscussed above, for example a circular tube.

An additional advantage that arises by having the tips curve towards acentral axis of the anchor when the anchor is in the foldedconfiguration is that less force is required to eject the anchor from acontainer device during implantation in body tissue. By having a smoothpoint of contact between the anchor and an inner surface of thecontainer device, the coefficient of friction between the anchor andsaid device is reduced. Thus less force is required to eject the anchorduring implantation.

The curving of the tips towards the central axis of the anchor when theanchor is in the folded configuration may be described as at least oneof, for example, a reverse curvature, an opposite curvature, or asigmoid curvature. In other words, in the folded configuration the hooksmay include a first curve portion extending towards the central axis ofthe anchor. The hooks and the tips may then curve away from the centralaxis of the anchor in a second curve portion, before the tip is formedto curve back towards the central axis of the anchor in a third curveportion. Thus the curvature of the hooks may be such that they have atleast one point of inflection.

Advantageously, the curvature of the anchor assists in pulling theanchor into the body tissue during implantation and thus reduces theforce required to push the anchor during implantation. As the anchorunfolds from its folded configuration to its unfolded configuration, thecurvature of the anchor provides a ‘springback’ force, wherein thecurvature of the hooks of the anchor assists in pulling the anchorthrough the body tissue. This advantageous effect is not exhibited byanchors having hooks which do not curve back towards a central axis ofthe anchor when in a folded configuration.

Anchors having hooks which do not curve back towards a central axis whenin a folded configuration tend to immediately bend back into theirunfolded configuration without penetrating any particular distance intothe tissue, unless a large amount of axial force is applied to theanchor during implantation. However, anchors having hooks where the tipsare formed to curve towards a central axis will tend to penetrate alarger distance into the body tissue before the tips begin to curveoutward from the central axis as they move into their unfoldedconfiguration. Thus a reduced axial force is required to be applied tothe anchor from the container device to cause the initial penetration ofthe anchor, and in some cases this may be no force with the unfolding ofthe anchor acting to draw it into the tissue so long as a distal end ofthe container device is in contact with the surface of the body tissue.The springback force of the anchor resulting from the inward curvatureof the tips facilitates a trajectory of the hooks of the anchor thatcause the anchor to move along a deeper curve into the tissue, therebycausing the pulling effect as described.

When the anchor is in the unfolded configuration the hooks may extendaway from the central axis of the anchor in a grappling hook type shape.Thus, the anchor may be configured such that when moving from the foldedto the unfolded configuration the tips move outwardly away from thecentral axis of the anchor. In the unfolded configuration the hooks mayhave a curvature with at least one point of inflection, for example thedirection of curvature of the hook may reverse at the tip. Thus, theunfolded configuration of the hooks may have a first curved portion witha first direction of curvature extending along the majority of thelength of the hook, followed by a second curved portion with an oppositedirection of curvature at the tip of the hook. This form can be used toensure that when folded into the folded configuration the tips willcurve inward toward the central axis as discussed above.

The curvature of the hooks of the anchor in its unfolded configurationas described above advantageously increases the planar extent of theanchor and thus increases the surface area covered by the anchor whenunfolded. As the anchor covers a larger surface area of tissue onceimplanted, the force of the anchor which acts on the tissue is equallyspread over a larger area. This reduces the strain on the body tissuethe anchor is implanted in. This is particularly advantageous in theimplantation of the anchor into lower quality or weaker body tissue.

The anchor may comprise a body portion from which the hooks extend. Forexample the body portion may include a tubular wall, with the hooksextending from the tubular wall such as from an end thereof. Thus, withthe curve described above in the folded configuration the first curveportion may extend from the tubular wall, followed by the other curveportion(s) extending further from the tubular wall. In exampleembodiments the hooks extend from the body portion with a smoothcurvature in both the unfolded and the folded configurations. In thatcase, there is no step change in the curvature at the point where thehooks join to the body portion (e.g. the tubular wall) or close to thatpoint. The hooks may extend from the body portion with an initial curvehaving a tangent aligned with the axial extent of the body portion inboth of the unfolded and the folded configurations. The curvature of thehooks may include no step change at all, so that it is always acontinuous curve with no sharp corners.

The curvature of the tips may result in the end of each hook beingconfigured to be perpendicular to the surface of the body tissue in thefolded configuration, i.e. when the anchor is implanted in the bodytissue the ends of the tips may be pressed into the body tissue toinitially pierce the body tissue in a direction that is perpendicular tothe surface of the body tissue. Typically this will involve at least thedistal portions of the tips being parallel with a longitudinal axis ofthe anchor and/or parallel to a direction of movement of the anchor asit is implanted. Advantageously, by having the ends of the hooksperpendicular to the body tissue less force is required to implant theanchor in the body tissue. This is because there is a higher conversionof the force pushing the anchor into the tissue being transferred toends of the tips, where initial implantation will occur. Moreover, byrequiring that the ends of the hooks be perpendicular to the body tissuethat the anchor is to be implanted in, the aligning of the anchor withthe body tissue will be easier.

Similarly, the curvature of the tips may result in the tip of each hookbeing configured to be at an angle to the surface of the body tissue inthe folded configuration, i.e. when the anchor is implanted in the bodytissue the ends of the tips may be pressed into the body tissue toinitially pierce the body tissue in a direction that is angled inwardsto the central axis of the anchor/acute to the surface of the bodytissue. Thus, the tips may curve toward the central axis and at leastthe end portions of the tips may extend diagonally toward the centralaxis, when in the folded configuration. The angle of the curvature ofthe tips may be any of any value in the range of 0 to 30 degrees to thenormal of the surface of the body tissue that the anchor is to beimplanted in. In various embodiments the range of values the curvatureof the tips could take may be 0 to 5 degrees, 0 to 10 degrees, 0 to 15degrees, 0 to 20 degrees, 0 to 25 degrees or 5 to 15 degrees.Advantageously, by having the tips of the anchor slightly angled to thebody tissue less axial force is required to fully implant the anchor inthe body tissue. The force may be applied to the anchor by the anchorcontainer tube, the anchor container tube comprising a number of wiresand/or rods for applying the axial force. This is because the springbackforce provided by the hooks of the anchor assists in pulling the anchorinto the body tissue. The springback force exhibited by the hooks of theanchor is increased depending on how inwardly curved the tips of theanchor are when initially implanted into the body tissue.

Thus, it will be appreciated that a consideration of the angle of thetips to a surface of the body tissue the anchor is to be implanted inmay be made to reduce the force required to implant the anchor fully inthe body tissue.

The tips of the hooks may include a tapering section extending to apointed end for piercing the body tissue. The tips may also include awidening section prior to the tapering section, with the wideningsection being wider than a preceding portion of the hooks. The shape ofthe tips of each hook may be that of a teardrop, a leaf, and/or a petal.That is, the tips may comprise a generally ovate shape comprising apointed end for engaging the body tissue. The shape of the tip may besuch that the widest portion of the tip is wider than that the width ofa preceding portion of the hook, with the point being of a narrowerwidth than that the width of the hook.

The shape of the tip being such that the tip is generally wider than therest of the hook may advantageously assist in strengthening theengagement of the anchor with the body tissue. When tissue regrowthoccurs around the implanted anchor, the tissue may regrow around thehook which extends through the body tissue. As the widest part of thetips of each hook are wider than that the width of the preceding portionthe hook, more force is required to remove an implanted anchor aftertissue regrowth has occurred as the shape of the tip itself forms afurther anchoring feature.

It will be appreciated that the anchor of this aspect may be used as aleaflet anchor or as a papillary anchor.

The anchor may further include that the hooks are formed with openingsalong their length. By adding openings in the anchor hooks a largerwidth hook can be used thereby increasing the holding strength whilestill allowing significant deformation between the folded and unfoldedconfiguration without any plastic deformation. The increased surfacearea of the larger width hook also aids in spreading the distribution offorces. The openings may also enhance healing by allowing tissue togrowing in between the slits, making a more reliable connection betweenthe anchor and the tissue over time, rather than the tissue forming a“sock” that may be pulled out more easily, as would be the case with asolid hook.

Advantages arise if the anchor can releasably hold a line such as achordae line, and therefore the anchor may comprise a locking mechanismfor clamping the line when no force is applied, and being able to beelastically deformed to release the line from the locking mechanism foradjustment of the length of the line. This may use a locking ring asdiscussed below.

In some examples the openings in the hooks include multiple holes (suchas multiple holes of with a diameter of about 0.2-0.4 mm), with theseopenings connected with a suture, wherein a single length of suturepasses through several of the multiple holes, or all of the multipleholes. The suture may be knotted at each hole. The suture may forexample be a Dyneema suture (or other similar suture, such as Dacron).Elastic materials such as nitinol can be prone to fatigue fracturingduring high cyclic loads, including the cyclic loads that will arisefrom a beating heart. By the use of a suture through multiple holes itis possible to add a failsafe to the anchor pins. If the hooks of theanchor break then the anchor is still kept together by the suture, whichreduces risk for embolism while also providing extra time for ingrowthof tissue. Thus, even if an anchor breaks at an early stage then it willnot embolise, and it will still be able to hold some force, as theexpanded anchor will be too large to be pulled through its entry holeeven if one or more hooks suffer a fracture. The use of a suture in thisway will also make more “openings” for tissue to grow through. Themultiple holes may be circular holes made in addition to other openingsin the hooks, such as being made in addition to slits as discussedbelow.

As an alternative to the use of a suture threaded through the openingsthe anchor may include an overmolding, which may be provided about theentire anchor excluding the sharp tips of the hooks could be possible. Asuitable material for such an overmoulding is ePTFE. Another alternativeis to use a woven fabric pouch that encloses the anchor. Both of thesesolutions would keep the anchor from embolising if there is a fracturein the anchor. The use of ePTFE also gives the added benefit of tissueingrowth.

The anchor may be formed from a tube that is cut to provide tinesextending from one end of the tube, with these tines then being curvedand heat set to form the hooks and tips. Openings can be cut into thetines before or after they are curved, but typically before in orderthat there is only one cutting stage. An added benefit of the use ofopenings in relation to this construction is that small diameter tubingbecomes more pliable with an opening in the centre, since the arc of thetube is divided into two smaller arcs. As a result a wider section of anarrow tube can be safely utilized for making the tines which againgives additional strength. As a result of the increased holding forceand increased pliability the anchor hooks are subjected to less fatigueload which in turn makes the implant last longer.

The openings may be formed as a series of holes, or as slits extendingalong the length of the tines to thereby extend along the curves of thehooks. A benefit of the use of slits is that each hook consists of two“legs” meaning that a fracture in one of the “legs” does not mean itwill embolise, and the anchor will still be held in place by the otherleg. At the same time the new “V” shape leg will highly likely grow intotissue more effectively than a straight “broken” hook without any slitor other openings, further reducing the danger of embolism.

The openings may include several smaller slits in line or have differenttypes of pattern (zig-zag, barbed or wave pattern are examples). Alongthe length of the hooks, small holes with different patterns may bemade, either instead of slits or in addition to slits. This can provideadditional holding force, when tissue grows through the holes. It canalso allow for a suture to be threaded through the hooks for addedsafety in the event of a fracture as discussed above. The slits may alsobe extended beyond the ends of the hooks where they join into the baseof the anchor, which may be a tube shaped part as discussed above,thereby making the base more flexible as well. In some examples theslits may be cut as a single laser track. Circular openings can be addedto the ends of such a cut to prevent high strain points.

In one example the anchor is cut from tubing made of an elastic metal,such as nitinol or stainless steel. Laser cutting may be used. This caninvolve cutting tines as discussed above, which can be heat set intocurves. The anchor may be heat treated and/or electropolished. Chamferededges may be introduced to the anchor on certain parts before the anchoris electropolished. The openings could contain a barbed or wave profilealong edges of the openings, e.g. along edges of slits. Where slits areused the slotted hooks can be heat set in a configuration where theyhave increased distance when deployed. A barbed profile can then beconcealed when the pins are straight (barbs are facing towards oneanother). With this example, when the anchor comes to a non-constrainedconfiguration then the slits move apart and the barb profile is engaged.

In various aspects the invention extends to the use of the catheterdevices and the anchors described above, and in particular to the use ofthose devices during a procedure for implanting an artificial chordaeline into the heart. Further, the invention extends to the manufactureof the catheter devices and the anchors described above, including thevarious method steps discussed above such as laser cutting from tubes.For any of the anchors, or other laser cut parts discussed hereinchamfered edges may be introduced before the laser cut part (e.g.anchor) is electropolished. The features of the third aspect and otheroptional features discussed above may be combined with the other aspectsdiscussed above and below, with the anchors of those other aspects hencehaving hooks formed in accordance with the third aspect.

Viewed from a fourth aspect the invention provides a catheter device forimplanting an anchor into body tissue to attach a line to the bodytissue, the catheter device comprising:

a housing section extending from a distal end of the catheter devicealong the length of the catheter device toward the proximal end of thecatheter device, the housing section comprising a distal part at thedistal end of the catheter device and a proximal part located on theproximal side of the distal part;

an anchor deployment mechanism at the distal part of the housing sectionfor deployment of the anchor for attachment of the anchor to the bodytissue, wherein the anchor deployment mechanism is arranged fordeployment of the anchor from a stowed position of the anchor by movingit outward in the distal direction relative to the distal part;

the anchor, which is held in its stowed position by the anchordeployment mechanism in the distal part prior to deployment, wherein theanchor is for implantation in the body tissue to hold a line, the anchorcomprising a number of hooks for engagement with the body tissue andhaving a folded position and an unfolded position, wherein the anchor ismade of an elastic material such that the hooks can be elasticallydeformed into the folded position by application of a constrainingforce, and will return to the unfolded position when no constrainingforce is applied, and wherein the hooks are held in the folded positionwhilst the anchor is in the stowed position within the distal part;

wherein the distal part of the housing has a non-circular shape forengagement with a corresponding non-circular form of the anchor and/orthe anchor deployment mechanism, such that when the anchor is held inthe distal part movement of the anchor is restrained with respect torotation of the anchor about a longitudinal axis of the distal part dueto engagement between the non-circular shape and the non-circular form.

With this arrangement the interaction of the non-circular shape of thedistal part with the non-circular form of the anchor or anchordeployment mechanism ensures that the anchor has a required orientationwhilst it is within the distal part. Rotation of the anchor isrestrained and advantageously may be prevented, at least with referenceto forces of a magnitude that the anchor and catheter device may beexposed to during normal use. Typically the restraint is provided byinterlocking of the non-circular form in the non-circular shape, with adesign tolerance in accordance with the appropriate manufacturingtechniques, materials and design principles. The non-circular elementsmay take any shape that is not circular. Some options are discussedbelow. The non-circular nature of the shape/form may be achieved bymodifying a circular form, such as by adapting it to be a keyed jointwherein the key or keyway contributes to the non-circular part of theshape. The catheter device may be for implanting the anchor into theheart and the anchor may be a papillary anchor for implantation into thepapillary muscle, with the line for example being an artificial chordaeline, such as a line used to repair the heart in the case of failingchordae tendineae. The restraint of rotation may hence be designed toresist forces that may seek to undesirably rotate the anchor during suchuse of the catheter device in the heart, or forces that arise whenretrieving a delivered anchor, to find the correct orientation of theanchor prior to retraction. Further features of a catheter device forimplantation of anchors into the heart are discussed below and it willbe appreciated that the catheter device of the fourth aspect may becombined with the further features as set forth below.

The non-circular shape may be a shape formed within the interior of thedistal part around a recess for housing the anchor and anchor deploymentmechanism, with the anchor in the stowed position. The non-circularshape may include a funnelled shape at the distal end thereof. This canallow for guided engagement of the anchor and anchor deploymentmechanism. For example, the non-circular shape may widen gradually as itapproaches the distal end of the distal part. The outer shape of thedistal part may be a different shape, for example it may be a tubularshape with a similar form to outer parts of the remainder of thecatheter device such as a circular tube. Advantageously, with the use ofa different outer shape compared to the inner, non-circular shape, thewall of the distal part may vary in thickness. Alternatively oradditionally the non-circular shape within the interior of the distalpart may be placed eccentrically, i.e. off-centre, in order to create avarying thickness of the wall of the distal part. Thicker sections ofthe wall may be able to better accommodate other features of thecatheter device, such as a chordae channel. By taking advantage of thevarying thickness in this way then such features can be added withoutincreasing the overall width/diameter of the catheter device. Thus, insome examples a thicker section of the wall of the distal part includesa chordae channel. The chordae channel may be a slit along the length ofthe distal part, which can usefully also have the function of increasingelasticity of the distal part allowing it to flex as it receives theanchor and the anchor deployment mechanism.

The anchor may include a locking mechanism with an elasticallydeformable locking segment as discussed further below. Alternatively,the locking mechanism may take another form, such as via parts that movein a rotational or linear sense in order to trap or restrain movement ofthe line, such as by an interference fit. The locking mechanism may befor locking the line in place after deployment of the anchor. The anchordeployment mechanism may be arranged to hold the locking segment in adeformed position when the anchor is stowed within the distal part, andadvantageously the locking segment may adopt a non-circular form when itis in the deformed position, with this non-circular form engaging with apart of the non-circular shape of the distal part of the catheterdevice. Thus, this part of the non-circular shape of the distal part ofthe catheter device may be arranged to engage with the anchor having thedeformed locking segment, wherein whilst the anchor is within the distalpart the respective non-circular elements are in engagement with eachother to thereby restrain rotation of the anchor within the distal part.In one example the locking segment is tubular when it is not deformed,and may align with a tubular wall of the anchor, with deformation of thelocking segment moving it out of alignment with the tubular wall of theanchor and hence forming the non-circular form for engagement with therelevant part of the non-circular shape of the distal part. The anchormay have a circular tubular wall, with the deformed locking segmenthaving a non-circular form with an ovoid shape where parts of thelocking segment protrude outward beyond the tubular walls of the anchor.In that case the distal part of the catheter segment may have acorresponding ovoid cross-section, or some other non-circularcross-section for complementary fit with a cross-section of the anchorwith the deformed locking segment. The distal part may hence include afirst tubular recess with this non-circular cross section, where thefirst tubular recess is formed contiguous with a second tubular recessto house the part of the anchor wall that is located at the proximalside of the locking segment. The second tubular recess may hence havecircular tubular form arranged to fit concentrically around the anchorwall proximal of the locking segment. Further optional features of alocking mechanism of the anchor are discussed below.

The anchor and/or a distal end of the distal part may be arranged todeform elastically during engagement of the anchor with the distal partin order to allow for guided engagement. Thus, the engagement of theanchor may be done with the ability to handle some misalignment byelastic flexing of the anchor and/or the distal end. The anchor may beinherently flexible due to its formation from an elastic material. Thedistal end may be adapted to allow for some degree of flexing, such asby the use of a slit extending from the tip along the length of thedistal end in the proximal direction.

The anchor deployment mechanism may comprise an adjustment housing thatholds the anchor during deployment and facilitates adjustment of a lineattached to the anchor. The adjustment housing may also include a cutterfor cutting of the line once the anchor has been successfully deployedin a desired location, with the line adjusted to a suitable length. Insome examples an outer part of the adjustment housing has a non-circularform and a part of the non-circular shape of the distal part of thecatheter device may be arranged to engage with the outer part of theadjustment housing with the respective non-circular elements inengagement with each other to thereby restrain rotation of theadjustment housing and hence assist in keeping the anchor from rotatingdue to attachment of the anchor to the adjustment housing whilst theanchor is within the distal part. The outer part of the adjustmenthousing may have a non-circular form at a proximal end thereof, i.e.opposite a distal end of the adjustment housing that couples with theanchor, with the distal part of the catheter device having a shape forreceiving this non-circular form. In this case the proximal end of theadjustment housing may advantageously have a tapering shape, such as viacurved, chamfered or bevelled edges, in order to allow for smooth andguided engagement of the proximal end with the corresponding part of thenon-circular form for the distal part.

A shaft which may house the cutter (and a wire to operate the cutter)and the adjustment housing can be built with two lumens: one chordae(i.e. line) lumen and one cutter wire lumen. The construction may bereinforced with braid around the chordae lumen. The braid may comprise alaser cut hypotube, which increases tensile and compression strength ofthe shaft. The laser cut hypotube may be welded directly onto a head ofthe cutter. This ensures a strong bond between the cutter and the lasercut hypotube, which allows for more reliable retrieval of the papillaryanchor if adjustment and/or redeployment of the anchor is required. Abraided composite tubing may be disposed outside the laser cut hypotubeto form the wire lumens. A Kevlar wire or a wire of a similar materialmay be disposed along the length of the shaft to increase the tensilestrength of the shaft. The components and tubing disposed in the shaftmay be embedded in a soft polymer, including but not limited to Pebax(e.g. by Pebax reflow), to allow for sufficient flexibility of theshaft. The composite tubing may also be anchored in the distal end toprevent the tubing from being torn out of the soft polymer duringactuation of the cutter wire. The composite tubing may be anchored inthe distal end with, for example, a flat ribbon coil, a stainless steelhypotube ring, or a collar.

The anchor and the adjustment housing may be arranged to engage witheach other in a required orientation with relative rotation prevented.In this context, as above, the rotation is restrained in a twistingdirection along the axis of a catheter device, i.e. the aim is tocorrectly orientate the anchor with respect to rotation about thelongitudinal axis of the catheter device. It is however an advantage toallow for some relative rotation during engagement of the anchor withthe adjustment housing in order to ensure the correct alignment withoutrisk of jamming. Thus, the anchor and the adjustment housing may eachhave circular parts for concentric engagement with each other includinga keyed joint to ensure correct alignment during the concentricarrangement. Thus, one of the anchor and the adjustment housing mayinclude a key feature, with the other including a keyway for receivingthe key feature. A funnelled/tapering shape at the start of the keywaymay be used to allow for some misalignment and guided rotation beforethe key feature engages with the keyway.

The distal part may have a non-circular shape that is arranged to engagewith both of a non-circular form of the anchor, such as the deformedlocking segment as discussed above, and a non-circular form of theadjustment housing, such as the outer part discussed above. Thus, thenon-circular shape of the distal part may be a complex shape with afirst part for engagement with the anchor and a second part forengagement with the adjustment housing. This can have added advantagescompared to the use of each element individually since both of the twoengagements contribute to restraining rotation of the anchor within thedistal part. The two engagements combined can also have a furtheradvantage through the different characteristics of the parts involved,such as a different degree of stiffness of the anchor compared to theadjustment housing, with the anchor being more easily elasticallydeformed; and/or a greater degree of flexibility during mating of thenon-circular shape and the non-circular form, for example via a largerdifference in dimensions where the non-circular form of the distal partfits around the anchor compared to where the non-circular form of thedistal part fits around the adjustment housing and/or greaterflexibility for the distal end of the distal part, such as through theuse of a slit as mentioned above.

In some examples the anchor is formed from an elastic material with arelatively flexible configuration, such as the anchors described furtherbelow, and it is more easily elastically deformed than the adjustmenthousing, which may include solid parts with a less flexibleconfiguration and/or may be formed from a less elastic material. Forexample, the anchor may have relatively thin walls formed of a flexiblemetal such as nitinol and the adjustment housing may be a solid shapeand/or have thicker walls formed of a stiffer material such as stainlesssteel, a polymeric material, or a composite material (e.g. CRF PEEK).Thus, during the re-engagement of the anchor with the distal part theengagement of the non-circular form of the anchor with the relevant partof the non-circular shape of the distal part may be done with elasticdeformation of the anchor and/or the distal end of the distal part inorder to cope with a relatively high degree of rotational misalignment,whereas the re-engagement of the adjustment housing with the distal partthe engagement of the non-circular form of the adjustment housing withthe relevant part of the non-circular shape of the distal part.

It can be required to move the anchor back from the unfoldedconfiguration to the folded, stowed, configuration during use, forexample if an initial deployment does not give a sufficiently secureconnection between the anchor and the body tissue. The catheter devicemay be arranged to facilitate re-engagement of the anchor and anchordeployment mechanism with the distal part by allowing for first are-engagement of the anchor with the distal part to correct forrelatively large rotational misalignment via the elasticity of thenon-circular form of the anchor and/or of the distal part of thehousing, and second to have a re-engagement of the outer part of theadjustment housing with the distal part to apply a greater restraintagainst rotation of the anchor within the distal part due to the morerigid form of the adjustment housing. The first part of the non-circularshape of the distal part of the catheter device may extend by a firstdistance in the distal direction from a fully stowed location of theanchor toward the distal end of the device. The second part of thenon-circular shape of the distal part of the catheter device may extendby a second distance in the distal direction from a fully stowedlocation of the adjustment housing toward the distal end of the device.To facilitate the above two-stage re-engagement process the firstdistance may be larger than the second distance, with the first parthence being larger than the second distance by a third distance. In anexample arrangement the first distance may be in the range 4-8 mm,whereas the second distance may be in the range 2-5 mm.

Thus, the anchor may engage elastically with the distal part over thethird distance, with this then providing some correction to thealignment of the rotational orientation of the anchor before theadjustment housing engages with the second part of the distal part overthe second distance. Whilst the adjustment housing engages with thesecond part of the distal part over the second distance the anchorprogresses further along the first distance, remaining in engagementwith the first part of the non-circular shape of the distal part.

The adjustment housing may form an anchor holder that connects to theanchor whilst it is stowed and during deployment and releases the anchorafter successful deployment of the anchor. An outer part of the anchorholder may have a non-circular form and this may provide the abovediscussed non-circular form of the adjustment housing for engagementwith the distal part. The anchor holder may be provided in two partsthat interlock with relative rotation between these two parts beingprevented by respective non-circular shapes, which may include flatsurfaces for correct alignment. The two parts of the anchor holder maycomprise a piston for engagement with the anchor and a piston housingfor holding the piston, with the piston able to be actuated for slidingmovement relative to the piston housing.

The piston may include a piston wedge for engagement with a deformableelement of the anchor, which advantageously is a locking segment asmentioned above. The piston wedge may be a wedge shaped section at thedistal end of the piston. The wedge-shaped section advantageouslyassists in engaging the locking segment and equally disengaging thelocking segment due to its shape. The piston wedge may be arranged to bepushed between the locking segment and the wall of the anchor toelastically deform the locking segment, advantageously forming thenon-circular form of the locking segment as well as opening the lockingsegment to allow for adjustment of the line. In that case, when theanchor is in the stowed position the piston wedge is engaged with thelocking segment. The piston wedge may be a two-legged fork with anopening allowing for the line to pass between the two legs (tines) ofthe fork.

The piston wedge may be engaged with the locking segment without beingin contact with any other wall of the papillary anchor. Thus, the anchorholder and the anchor may be arranged such that when the piston wedge isengaged then it is spaced apart from the wall of the anchor. Byadvantageously requiring that the piston wedge is in contact with thelocking segment of the anchor alone, and not any other wall of theanchor, the piston wedge experiences less friction from the anchor. Assuch, during deployment of the anchor from the catheter device, theanchor may deploy without the piston wedge moving with the anchor tothus ensuring the locking of the locking segment. The placement of thepiston in the anchor holder acts as a cantilever, which prevents thepiston wedge from being pulled towards the wall of the anchor due to theelastic force of the locking segment. The piston and hence the pistonwedge may be made of a suitably rigid material, such that the pistonwedge is not bent out of shape by the reaction force due to thecantilever action of the piston and the force exerted on the pistonwedge by the locking segment acting in opposite directions.

The piston may include the cutter of the adjustment housing, with thiscutter being arranged to cut the line when the piston is withdrawn fromthe anchor. The cutter on the piston may be a cutting surface arrangedto interact with a surface of the piston housing to cut the line, suchas via a shearing action. Thus, where a piston wedge is used then thewithdrawal of the piston may allow the line to be locked in place at theanchor as the locking segment returns to its undeformed position andclamps the line to the anchor wall, whilst the line is simultaneouslycut by the cutter. In this way the piston aids in an adjustment andcutting procedure once the anchor is correctly placed and the length ofthe line is as required.

An internal cam may be provided for aiding in holding the anchor lockingsegment in an open position. The internal cam may have an unexpandedconfiguration where the cam fits inside the locking segment in theundeformed state of the locking segment, and an expanded configurationwhere the cam fits inside the locking segment in the deformed state,i.e. the non-circular form discussed above. The cam may have an openingat its centre that is wider in the expanded configuration than in theunexpanded configuration. The piston may be provided with a cam wedgefor urging the opening of the cam to the wider state and hence expandingthe cam. The cam wedge may be provided in addition to the piston wedgediscussed above, so that a single piston has a fork like form at itsdistal end, with at least one tine of the fork providing the cam wedgeand at least one tine of the fork providing the piston wedge. The cammay be arranged aid opening of locking segment and it may also act tofix the anchor to the adjustment catheter, where present. The cam may beheld in place by a cam holder on the adjustment housing.

The catheter device may include a mechanism for control of movement ofthe adjustment housing relative to the distal part, for example to pushthe adjustment housing and the anchor outward from the distal part inthe distal direction to deploy the anchor. This mechanism may include anadjustment catheter located within the housing of the catheter device,where the adjustment catheter can be moved forward or backward along thelength of the catheter device in order to advance or retreat theadjustment housing. Wires and/or rods may be used to control movement ofthe adjustment housing, with manual or computer controlled movement viacontrol system arranged to be placed outside of the body.

The catheter device may include a mechanism for control of movement ofthe piston relative to the piston housing. This may include wires and/orrods of suitable type. The mechanism may be arranged to slide the pistonoutward from the piston housing in order to move the anchor away fromthe piston housing. The mechanism may be further arranged to draw thepiston back into the piston housing to either disengage the piston fromthe anchor or to draw the anchor back toward the piston housing alongwith the piston. It will be appreciated that to complete the deploymentof the anchor after the line has been suitably placed and adjusted thenthe piston should withdraw from the anchor to disengage therefore, suchas by removing the wedge from the locking segment, where present.However, if it is determined that the anchor is not placed correctlythen the user may decide to draw the anchor back toward the pistonhousing in order to then pull the anchor along with the adjustmenthousing back into the distal part to withdraw the anchor from the bodytissue and fold the hooks back into the folded, stowed position.

To prevent the cutter from exceeding its desired range of motion, thecutter may be equipped with two stopping features disposed at an upperand lower end of the cutter. To prevent the cutter from moving furtherthan its upper position in the housing, a cutter wire may be threadedthrough the housing and/or the cutter to stop the cutter in an upperposition. Even if the cutter wire were to break, the cutter and a wireattached to the cutter operating it cannot escape from an upwards end ofthe housing as both are contained within the housing. To prevent thecutter from moving further than its lower position in the housing, a camor the internal cam may function as the lower position stopping feature.

The adjustment housing may include a latch for engagement with thehousing section of the catheter device in order to prevent movement ofthe adjustment housing relative to the catheter device, and this may befor providing a secure state where the anchor cannot be released. Such asecure state can be beneficial whilst the catheter device is beingsteered to the deployment position, such as being steered through ablood vessel to reach the heart as in the examples below. The latch maybe pivoted about an axis extending along the longitudinal axis of thecatheter device in order to allow it to swing into and out of engagementwith the housing section, for example with engagement into a recess orslot formed in the housing section. A wire or rod may be included foractuation of the latch, such as a wire that blocks movement of the latchto keep the secure state until the wire is removed. The latch may besprung and biased toward a disengaged position, so that when the wire isremoved and the latch is released it moves under the influence of aspring force into the disengaged position.

In some examples, the anchor is provided with a locking mechanism thatclamps the chord when no force is applied, and that can be elasticallydeformed to release the chord for adjustment of the length of the chordduring implantation thereof. As noted above, the locking mechanism maycomprise a resiliently deformable locking segment. The locking segmentmay be formed in a wall of the anchor and divided from the wall by oneor more slit(s). The anchor may be arranged so that when no forced isapplied then the slits are closed with no gap or a relatively narrow gapin order to clamp the line, whereas when a suitable force is applied tothe locking segment and/or wall then the locking segment and/or the wallwill elastically deform to widen the opening provided by the slit(s) sothat the line is released. The anchor may have a tubular body section,in which case the locking segment may be formed in the wall of the tube.The locking segment may be a band with parallel slits on two sides, suchthat the band can be pulled out of plane with the wall by application ofa force in order to open up the slits. Advantageously, this movement ofthe locking segment may create the non-circular form for the anchor.Such a locking segment can be held open by sliding a holder into theslit(s), such as the piston discussed above.

The housing section may be formed from one or more tubular sections inany suitable material, i.e. a medically appropriate material. Stainlesssteel or nitinol may be used. Polymeric materials are also an option. Inthe alternative, composite materials such as carbon-fibre or glass-fibrereinforced PEEK may be used. The catheter device may be formed via acombination of such materials with the materials for different parts ofthe device being selected dependent on the required characteristics ofthose parts. A material that allows ultrasound to pass through and atthe same time have sufficient strength is preferred, carbon reinforcedPEEK meets these demands well, and would also allow injection mouldingof the components which lowers manufacturing cost. Fibre reinforcedplastics are normally not visible on X-ray, so strategically placedradiopaque markers in all components may be used to determine devicecomponent(s) position and orientation on X-ray relative to each other,as complementary information to ultrasound imaging.

As mentioned above the catheter device may be for implanting the anchorinto the heart and the anchor may be a papillary anchor for implantationinto the papillary muscle, with the line for example being an artificialchordae line. The catheter device may also be arranged for implanting aleaflet anchor along with the papillary anchor into the heart as part ofa procedure for implanting an artificial chordae line that extendsbetween the leaflet anchor and the papillary anchor. Thus, the catheterdevice may further include the leaflet anchor and a leaflet anchordeployment mechanism.

Thus, the housing section may be a two-part housing section, thetwo-part housing section being arranged to be placed between thepapillary muscle and a leaflet of the heart during use of the catheterdevice, and the two-part housing section comprising a distal part at thedistal end of the catheter device and a proximal part located on theproximal side of the distal part; wherein the distal part holds thepapillary anchor deployment mechanism, i.e. the anchor and adjustmenthousing as discussed above, and the proximal part holds the leafletanchor deployment mechanism.

The leaflet anchor and/or the leaflet anchor deployment mechanism may besimilar to that of WO2016/042022. Alternatively or additionally theleaflet anchor and the leaflet anchor deployment mechanism may havefeatures as discussed below.

An example of the use of the catheter device of the fourth aspect mayinclude the following steps: (1) the device is first placed in nearproximity to final placement; (2) the distal part is moved toward thebody tissue that is to receive the anchor; (3) the distal end of thedistal part meets the body tissue, and as force is applied thecounterforce from the body tissue eventually surpasses the forcesholding the anchor in place, at this point tissue is pushed flat belowthe base of the device giving a maximal chance of placing all hooks ofthe anchor correctly in tissue, and force can be applied to the anchorso that the ends of the hooks then move beyond the distal end of thedistal part to meet the body tissue, this may be done via additionalforce on the anchor and/or the anchor deployment mechanism from rods orwires, or advantageously it may be done through a pre-tension on theanchor that is held by friction with the distal part until the forcesfrom the body tissue on the distal part changes the balance of forceswith the friction sufficiently so that the anchor ejects (similar to apaper stapler); (4) the anchor hooks fold out and form into the hookshape of the unconstrained anchor to thereby engage with the bodytissue, at which point the connection can be pull tested by operator,and/or visually confirmed on x-ray and/or ultrasound; (5) if theconnection is not satisfactory, the anchor can be pulled back into thedevice and re-placed to attempt an improved coupling of the anchor withthe body tissue.

Viewed from a fifth aspect, the invention provides a method of use ofthe catheter device of the fourth aspect for implanting an anchor intobody tissue, the method comprising: deployment of the anchor into thebody tissue using the anchor deployment mechanism. The method mayadvantageously include testing the connection of the anchor beforedisengagement of the anchor from the anchor deployment mechanism andfrom the catheter device. In the case of an unsatisfactory deployment ofthe anchor the method may include withdrawing the anchor from the bodytissue and moving the anchor along with the anchor deployment mechanismback into the distal part, with the non-circular shape of the distalpart coming into engagement with a corresponding non-circular form ofthe anchor and/or the anchor deployment mechanism in order that theanchor is in the correct orientation once it is back in its stowedconfiguration within the distal part. This method may include use of adevice with any of the other features discussed below in connection withthe other device and method aspects of the present disclosure.

Viewed from a sixth aspect the invention provides a catheter device forimplanting a leaflet anchor during a procedure for implanting anartificial chordae line into the heart, the catheter device comprising:a leaflet anchor for attachment to the leaflet of the heart; and aleaflet anchor deployment mechanism for deploying the leaflet anchor;wherein the leaflet anchor deployment mechanism allows for retractionand repositioning of the leaflet anchor after deployment of the anchorinto the leaflet via an ejector unit having a grasping device with afirst configuration arranged to permit deployment of the leaflet anchorinto the leaflet without disengagement of the leaflet anchor from theejector unit, and a second configuration in which the leaflet anchor isreversibly released from the ejector unit; wherein in the firstconfiguration the grasping device of the ejector unit grasps a proximalend of the leaflet anchor, whilst a distal end of the leaflet anchor isunimpeded by the grasping device to enable it to be implanted in theleaflet; and wherein in the second configuration the grasping device ofthe ejector unit is disengaged from the leaflet anchor.

The leaflet anchor may be retracted with a retraction tube/catheter, bypulling the chordae so the leaflet anchor folds inside the retractiontube. The retraction tube may be placed on top of a chordae onlyattached to the leaflet (with device removed) or a leaflet anchor placedin a poor location (partly engaged, free floating, entangled etc.). Theretraction tube may be a deflectable shaft, with or without a flexiblesection on the tip (that allows the tip to find the leaflet anchor base,to allow retraction). Alternatively the retraction shaft may be aflexible tube that is arranged to engage with the base of the leafletanchor. In either configuration a marker band in the tip is needed toconfirm that the retraction tube is at the base of the leaflet anchor,prior to applying tension to the chordae, to prevent any unwanted damageto the implant or native tissue.

Another alternative to retract the leaflet anchor when it is freefloating (not attached to anything) is to tension the chordae until theleaflet anchor can be folded inside the papillary anchor housing, eitherin the distal end or through an opening in the papillary anchor housingwall.

As will be seen from review of WO2016/042022, in this earlier proposalthe leaflet anchor is pushed out once the gripper of the leaflet anchordeployment mechanism holds the leaflet and after being pushed out theleaflet anchor cannot be retrieved with the same mechanism. Whilst it ispossible to retrieve the leaflet anchor with the device ofWO2016/042022, there is only one relatively complex way described to dothis, and it involves a separate retrieval catheter. With the catheterdevice of the sixth aspect, in order to give the physician additionalcontrol, an “ejector unit” is introduced that allows for the leafletanchor deployment mechanism to deploy and also retrieve the leafletanchor.

It will be appreciated that the features of the device of the sixthaspect may be combined with those of the second aspect, therebyachieving the advantage of each. Moreover, there is synergy in thiscombination since the ability to remove and replace the leaflet combineswith the benefits of the ability to keep the catheter device in place atthe leaflet whilst the papillary anchor is inserted via use of theflexible and optionally extendable joint. This allows for the surgeonmaximum flexibility in terms of insertion of the two anchors andchecking of the connections before any significant motion of the deviceis needed away from its position at the leaflet anchor. The device mayalso be moved from the leaflet anchor placement position to accommodatepapillary anchoring position or the other way around.

The telescopic shaft that holds the device may be fitted with 4pullwires, so that the distal tip can move in order to locate correctvalve position for placing the anchor(s).

The leaflet anchor may be formed from a flexible material with a hookedshape in an unfolded configuration, and being able to deform elasticallyinto a folded configuration, for example when constrained by the leafletanchor deployment mechanism. The material of the leaflet anchor may benitinol. The shape of the leaflet anchor may include hooks that arestraightened out when the leaflet anchor is in the folded configuration.The hooked shape of the unfolded configuration may be a grapple hookshape, for example. The leaflet anchor may have a similar form to thatof WO2016/042022 and/or may have features as described below. In exampleembodiments, the leaflet anchor and leaflet anchor deployment mechanismmay be arranged such that the when the leaflet anchor is pushed out ofthe leaflet anchor deployment mechanism then this can drive the hooksthough the leaflet whilst the hooks return elastically to the unfoldedconfiguration, thereby securing the leaflet anchor in the leaflet.

In example devices the chordae sits inside a groove in the device, afterthe leaflet anchor is placed, and applying tension (shortening) of thechordae may be used in order to release the chordae from the groove itsits in. Removing slack in the system can reduce the chance of thechordae wrapping around the device, creating complication. An example ofa device to reduce slack may be some sort of constant tension device,such as a constant force spring. The constant tension device may bedisposed in a delivery handle of the device.

The ejector unit may be placed within the leaflet anchor deploymentmechanism inboard of the leaflet anchor. With this arrangement, when theejector unit and leaflet anchor are within the leaflet anchor deploymentmechanism then the ejector unit holds the leaflet anchor with thegrasping device in the first configuration. The leaflet anchordeployment mechanism can deploy the anchor to implant it in the leaflet.In example embodiments, the grasping device may be arranged to remain inthe first configuration during this deployment, with the ejector unitbeing arranged so that it moves to the second configuration only afterthe leaflet anchor is implanted. With the leaflet anchor implanted thegrasping device can be used to test the connection of the anchor to theleaflet, by a force being applied to the leaflet anchor from the ejectorunit whilst the grasping device is in the first configuration. Anotherway to test the connection is to assess leaflet movement compared to theblood flow, with the leaflet attached to the leaflet anchor and therebyheld to the catheter device, i.e. before the leaflet anchor is released.If the leaflet anchor is well-engaged then the movement of the leafletwill be more restricted than if it is not well-engaged. Subsequently,with the ejector unit moved into the second configuration, the graspingdevice of the ejector unit opens and at this point the physician mayfurther test the connection of the anchor to the leaflet, for examplevia tension applied to the chordae line. If the physician is notsatisfied (for example, if there is too much movement of the anchorand/or not enough resistance to force on the line) then the leafletanchor can be retracted and placed in another location. If the graspingdevice did not change from the first configuration during the test thenthe latter procedure may be carried out by reversing the deployment ofthe ejector unit and leaflet anchor, for example by drawing those partsback into the leaflet anchor deployment mechanism. If the secondconfiguration was used before it was determined that the connection ofthe anchor was not adequate then to retract the anchor the ejector unitis first moved back to the first configuration so that the graspingdevice reengages with the leaflet anchor, and then after that thedeployment of the ejector unit and leaflet anchor is reversed, forexample by drawing those parts back into the leaflet anchor deploymentmechanism.

The use of the device of the sixth aspect reduces the risk of a badlyconnected leaflet anchor requiring the procedure to be aborted andstarted over, and this reduced risk has clear benefits for theefficiency of the procedure as well as for the health of the patient. Inaddition the retractable feature may allow the physicians to load andreload the catheter device with leaflet anchors more easily. A reloadingoperation can be necessary if multiple chordae lines are needed to beplaced in a single surgical procedure. The method steps during assemblyof the device will also be improved.

In some examples, both of the leaflet anchor and the ejector unit arehoused inside a leaflet anchor tube of the leaflet anchor deploymentmechanism prior to deployment, with the ejector unit further inside theleaflet anchor deployment mechanism than the anchor. The leaflet anchortube may have a shape that is complementary to the shape of the leafletanchor, i.e. with a similar cross-sectional shape. In some examples bothof the leaflet anchor and the tube both have a circular cross-sectionwith the leaflet anchor in the deformed configuration and placed intothe tube. As discussed above the leaflet anchor may unfold into a hookedshape, in which case it may comprise hooks extending from a tubular bodysection. The ejector unit may also have a shape that is complementary tothe shape of the leaflet anchor, i.e. with a similar cross-sectionalshape, and this may hence also be a circular cross-section.

The leaflet anchor tube has an opening that can be directed toward theleaflet. This opening may not be at a distal end of the catheter deviceas a whole. In fact the opening of the leaflet anchor tube mayadvantageously be directed toward the proximal end of the catheterdevice, in order that the leaflet anchor may easily be inserted throughthe leaflet from the bottom of the leaflet, as is required for effectiveimplantation of an artificial chordae line that extends from the leafletanchor to a papillary anchor at the papillary muscle. The leaflet anchortube may be within a gripper arrangement as disclosed in WO2016/042022and/or may have features as described below. Thus, the leaflet anchordeployment mechanism may include a gripper for gripping the leafletduring deployment of the leaflet anchor. It can provide advantages ifthe catheter device combines the proposed ejector unit of this aspectwith a gripper that is different to WO2016/042022 as discussed below,i.e. wherein the leaflet anchor is deployed with the gripper at an angleto the main body of the catheter device.

With arrangements using a leaflet anchor tube, the leaflet anchor may bearranged to be deployed by advancing both the leaflet anchor and theejector unit along the tube, with the leaflet anchor having pins at itsdistal end that form into the hooks of a hooked shape as the pins leavethe opening of the leaflet anchor tube. This can be done whilst theleaflet is gripped in a gripper of the leaflet anchor deploymentmechanism as discussed above. As noted above, once the leaflet anchor isimplanted then the connection can be tested in relation to position andholding strength. If needed then the leaflet anchor can be pulled backinto the leaflet anchor tube to release it from the leaflet. If theconnection of the anchor is acceptable then the ejector unit may beadvanced further in order that the leaflet anchor is released.

Thus, in some examples, the change from the first configuration to thesecond configuration may be actuated by movement of the ejector unitalong the leaflet anchor tube, for example by permitting the graspingdevice to open when it reaches a certain position in the tube. In oneexample the ejector unit has a constrained configuration as the firstconfiguration, and a non-constrained configuration as the secondconfiguration. In the first configuration the ejector unit holds theleaflet anchor with the grasping device, which may for example comprisetwo or more grappling hooks arranged to engage with the leaflet anchorat their ends. In one possible arrangement the grappling hooks have endsthat engage with holes formed in the leaflet anchor, preferably aproximal end of the leaflet anchor with respect to the distal directionalong the leaflet anchor tube. The grasping device may engage anddisengage from the leaflet anchor via a radial movement relative to theleaflet anchor tube. Thus the constrained, first, configuration mayinvolve walls of the leaflet anchor tube preventing an outward radialmovement of the grasping device (such as of the grappling hooks) inorder to force the ejector unit to remain engaged with the leafletanchor. In the non-constrained, second, configuration grasping devicereleases the leaflet anchor, for example via the grappling hooks movingapart. The transition from the first configuration to the secondconfiguration may occur by movement of the ejector unit to a point atwhich a constraint from the walls of the leaflet anchor tube is removed,so that the grasping device opens, for example by an outward radialmovement of the grappling hooks. This may be due to a movement of partsof the ejector unit out of the leaflet anchor tube, i.e. out of theopening at the tube's distal end, or it may arise by movement of partsof the ejector unit to align with cut-outs in the walls of the leafletanchor tube.

The movement of the leaflet anchor and ejector unit within the leafletanchor deployment mechanism, for example along the leaflet anchor tubedescribed above, can be actuated by wires and/or rods. A wire may beprovided for pulling the ejector unit for retraction of the ejectorunit. Retraction of the ejector unit may be required either after asuccessful implantation of the leaflet anchor or as part of a retractionof the leaflet anchor to allow it to be re-implanted. Since the leafletanchor tube may be directed toward the proximal end of the catheterdevice, as discussed above, such that the retraction of the ejector unitrequires a pulling force toward the distal end of the device, then thewire for retraction may pass around a pulley or the like. A rod may beused for deployment of the leaflet anchor, i.e. for moving the ejectorunit together with the leaflet anchor along the leaflet anchor tubetoward the opening at the tube's distal end. To allow for a pushingforce directed toward the proximal end of the catheter device then therod may be a U-rod. This may be arranged as described in WO2016/042022.A rod for deployment may also be capable of applying a pulling force forretraction and hence a rod may be used alone. Alternatively, the rod maybe used for deployment with a wire as discussed above being used forretraction. In another alternative the ejector unit can be moved by twowires and pulleys providing for movement in both directions. The U-rodmay be produced form a heat set or bent wire. With one or more bend(s)to make the U shape and the shape that pushes on the leaflet anchor.

A groove may be provided in a wall of the leaflet anchor tube forguiding the ejector unit. The groove may ensure that the ejector unitremains a single orientation relative to the tube while it is moved upand down. The groove may alternatively or additionally set maximumlimits on the range of movement of the ejector unit, and thus mayprevent it from going too far in either direction, out of or into theleaflet anchor tube. The ejector unit may be provided with a guide pinfor engagement with the groove. Advantageously, a narrowing in thegroove may be provided to act as an indicator to let the operator knowwhen the ejector unit has reached a certain position. The size of theguide pin and the width of the narrowing may be set so that engagementof the pin with the narrowing in the groove will require an increasedforce before further movement can be made, thus providing tactilefeedback to the operating physician.

In one example a force feedback mechanism, such as the narrowing, isprovided in order to signify that the leaflet anchor has been moved tothe deployed position, but that the ejector unit is still in the firstconfiguration so that the anchor is still retractable. In this case,once the ejector unit is pushed further (e.g., so that the guide pin isbeyond the narrow section) then the ejector unit may move to the secondconfiguration so that the leaflet anchor will be released from theejector unit. Thus, in one example constrained parts of the ejectorunit, such as the grappling hooks discussed above, may be released fromtheir constraint once there is movement beyond a point of actuation ofthe force feedback mechanism, such as when the guide pin passes thenarrowing in the example above. Alternatively or additionally there maybe feedback mechanisms in the operation handles of the catheter devicethat can indicate the position of the ejector unit, for example byvarying forces or by visual indicators. In an alternative to a guide pinand narrowing groove system another form of force feedback mechanism mayact on the guide pin, for example a “shear-pin” suture that breaks at agiven point with a given load.

The leaflet anchor deployment mechanism may include a line pusher fordirecting a line out of and away from the leaflet anchor deploymentmechanism during deployment of the leaflet anchor. When the device is inuse there may be a line attached to the leaflet anchor. The line may beprovided to form the artificial chordae line after the leaflet anchor isimplanted, or to allow the artificial chordae line to be attached to theleaflet anchor. The line may be a suture such as a Goretex ePTFE suture.The line pusher advantageously directs the line away from the leafletanchor deployment mechanism so that it can be more readily accessed forlater manipulation, such as for tightening the line or for pulling onthe implanted leaflet anchor for testing of the connection. The linepusher may be actuated during the action of deployment of the leafletanchor, and in some examples it is actuated when the leaflet anchor isreleased from the ejector unit. Thus, the line pusher may be releasedwhen the ejector unit withdraws away from the implanted leaflet anchor.The line pusher may transition from a constrained state to anon-constrained state in a similar way to the grappling hooks describedabove, and thus it may move radially outward to push the line out, withthis radially outward movement being permitted and the line pusherreleased once a constraint is removed. The constraint may be from theleaflet anchor, and thus the constraint may be removed, when the ejectorunit is pulled back into the leaflet anchor deployment mechanism. Inthat case the line pusher may be an arm that extends axially forwardfrom the ejector unit toward the leaflet anchor, and radially outward ofthe leaflet anchor tube when the arm is at rest with no forces applied.Prior to deployment of the leaflet anchor the arm of the line pusher isbent elastically to place its distal end within the leaflet anchor, sothat it is constrained and cannot move to its radially outward positionuntil the leaflet anchor and the ejector unit move apart. In someexamples, as the ejector unit continues to withdraw into the leafletanchor deployment mechanism the line pusher may remain in itsunconstrained state with the line pusher as well as the line beingpushed out of a slit in the leaflet anchor deployment mechanism, such asa slit along the leaflet anchor tube.

The catheter device of the sixth aspect may further be provided with apapillary anchor and papillary anchor deployment mechanism fordeployment of a papillary anchor for attachment to the papillary muscle.The papillary anchor deployment mechanism may be arranged for deploymentof the papillary anchor by moving it outward in the distal directionrelative to the distal part. The papillary anchor deployment mechanismmay be arranged within a two-part housing section as discussed abovewith reference to the second aspect, in which case the leafletdeployment mechanism may be in the proximal part of the two-part housingsection. Alternatively, the papillary anchor deployment mechanism may besimilar to that described in WO2016/042022. In some examples theactuation of the leaflet anchor may be connected to the papillary anchordeployment, meaning that the leaflet and papillary anchor may bearranged to be at least party deployed at the same time, for examplebeing actuated by a single control wire or rod. This can make theprocedure easier and/or faster.

The papillary anchor deployment mechanism may include a lock thatprevents the papillary anchor from ejecting too early, which may happenif the outer shaft that holds the device is compressed, while the innerpapillary anchor deployment shaft is stretch or keeps it original lengthwhile the outer shaft is shortened, pushing the papillary anchor out ofits housing. The lock may be a flip out tab that holds the anchoradjustment and ejector mechanism in place, the tab may be operated witha torque, push or pull wire or a suture. The actuation wire/suture maybe routed through the gripper housing and supported there or supportedin the papillary housing, alternatively anchored in the anchordeployment mechanism itself. In a second configuration the lockingmechanism may sit inside the papillary anchor deployment mechanism andbe actuated by a wire that goes inside the adjustment catheter. As notedabove, wire(s) and/or a rod can be used to deploy and/or retract theejector unit. In another variation the ejector unit may be moved via asliding sheath that engages with a lug on the ejector unit. This sheathmay fit around the leaflet anchor tube. The sheath may be a partialtube, such as a three quarter tube, that goes around the leaflet anchortubing. Such an arrangement may also be called “sledge”, or a “linearmotion bearing”. The sheath when moved will push on the lug of theejector unit. The sheath may be actuated by one or more wire(s) orrod(s), which may be connected with a rotational joint to the sheath.For example, there may be one or more wires that can be pulled or pushedby the operator. Nitinol wires may be used. When pulled or pushed thesheath translates along the outside of the leaflet anchor tube, forexample to move towards the opening of the tube and push the ejectorunit via the lug. The lug may be the guide pin in the groove asdiscussed above.

The ejector unit and/or the leaflet anchor may be produced from anelastic metal, such as nitinol. The ejector unit and/or the leafletanchor may be laser cut, heat set and electropolished metal tubing. Theguide pin and/or lug, where present may be welded into place afterassembly, such as by laser welding. The grappling hooks of the ejectorunit may be heat set or laser welded in place, and they may have anysuitable shape for engagement with the leaflet anchor. The leafletanchor tube may be attached to the leaflet anchor deployment mechanism,such as attachment to the gripper, by welding, soldering or gluing, orit could be cut from a solid piece via subtractive manufacturing.Additive manufacturing techniques might also be used. Additional tubesmay also be provided next to the leaflet anchor tube, for example toprovide fluid flow or for covering wires. At the end of the leafletanchor tube there may be a gripper tip that extends laterally around theleaflet anchor tube to form a gripping platform that fits with anopposing gripper element of the leaflet anchor deployment mechanism. Thegripping platform may be formed by filling an end of the gripper withresin. The leaflet anchor tube may have a lever arm attached, such as aheat set (or squashed) flat section or a bent section, wherein the leverarm stretches past a rotation axis (the rotation axis may move duringthe gripper arms movement) of the gripper to attach wires used to openand/or close the gripper.

The leaflet anchor tube may be laser-welded to a gripper tube section,inside the chordae slit. Further features of possible gripperarrangements may be similar to those disclosed in WO2016/042022 and/ormay be as set out below.

Viewed from a seventh aspect present invention provides an anchor forimplantation in body tissue to hold a line, the anchor comprising anumber of hooks for engagement with the body tissue and having a foldedposition and an unfolded position, wherein the anchor is made of anelastic material such that it can be elastically deformed into thefolded position by application of a constraining force, and will returnto the unfolded position when no constraining force is applied, andwherein the hooks are formed with openings along their length, whereinthe openings in the hooks comprise slits extending along some or all ofthe length of the hooks.

It will be appreciated that the anchor of this aspect may be used as aleaflet anchor or as a papillary anchor. By adding openings in theanchor hooks a larger width hook can be used thereby increasing theholding strength while still allowing significant deformation betweenthe folded and unfolded position without any plastic deformation. Theincreased surface area of the larger width hook also aids in spreadingthe distribution of forces. The openings may also enhance healing byallowing tissue to growing in between the slits, making a more reliableconnection between the anchor and the tissue over time, rather than thetissue forming a “sock” that may be pulled out more easily, as would bethe case with a solid hook.

A benefit of the use of slits is that each hook consists of two “legs”meaning that a fracture in one of the “legs” does not mean it willembolise, and the anchor will still be held in place by the other leg.At the same time the new “V” shape leg will highly likely grow intotissue more effectively than a straight “broken” hook without any slitor other openings, further reducing the danger of embolism.

It will be appreciated that the anchor of this aspect, as well asproviding its own advantages, may also combine synergistically with thecatheter devices of the aspects described above. Thus, anchors havinghooks with openings may be used for the leaflet anchor and/or thepapillary anchor of the above aspects.

Advantages arise if this anchor can releasably hold a line such as achordae line, and therefore the anchor may further comprise a lockingmechanism for clamping the line when no force is applied, and being ableto be elastically deformed to release the line from the lockingmechanism for adjustment of the length of the line. This may use alocking ring as discussed below.

In some examples the openings in the hooks include multiple holes (suchas multiple holes of with a diameter of about 0.2-0.4 mm), with theseopenings connected with a suture, wherein a single length of suturepasses through several of the multiple holes, or all of the multipleholes. The suture may be knotted at each hole. The suture may forexample be a Dyneema suture (or other similar suture, such as Dacron).Elastic materials such as nitinol can be prone to fatigue fracturingduring high cyclic loads, including the cyclic loads that will arisefrom a beating heart. By the use of a suture through multiple holes itis possible to add a failsafe to the anchor pins. If the hooks of theanchor break then the anchor is still kept together by the suture, whichreduces risk for embolism while also providing extra time for ingrowthof tissue. Thus, even if an anchor breaks at an early stage then it willnot embolise, and it will still be able to hold some force, as theexpanded anchor will be too large to be pulled through its entry holeeven if one or more hooks suffer a fracture. The use of a suture in thisway will also make more “openings” for tissue to grow through. Themultiple holes may be circular holes made in addition to other openingsin the hooks, such as being made in addition to slits as discussedbelow.

As an alternative to the use of a suture threaded through the openingsthe anchor may include an overmolding, which may be provided about theentire anchor excluding the sharp tips of the hooks could be possible. Asuitable material for such an overmoulding is ePTFE. Another alternativeis to use a woven fabric pouch that encloses the anchor. Both of thesesolutions would keep the anchor from embolising if there is a fracturein the anchor. The use of ePTFE also gives the added benefit of tissueingrowth.

The anchor may be formed from a tube that is cut to provide tinesextending from one end of the tube, with these tines then being curvedand heat set to form the hooks. Openings can be cut into the tinesbefore or after they are curved, but typically before in order thatthere is only one cutting stage. An added benefit of the use of openingsin relation to this construction is that small diameter tubing becomesmore pliable with an opening in the centre, since the arc of the tube isdivided into two smaller arcs. As a result a wider section of a narrowtube can be safely utilized for making the tines which again givesadditional strength. As a result of the increased holding force andincreased pliability the anchor hooks are subjected to less fatigue loadwhich in turn makes the implant last longer.

The openings may include several smaller slits in line or have differenttypes of pattern (zig-zag, barbed or wave pattern are examples). Alongthe length of the hooks, small holes with different patterns may bemade, in addition to slits. This can provide additional holding force,when tissue grows through the holes. It can also allow for a suture tobe threaded through the hooks for added safety in the event of afracture as discussed above. The slits may also be extended beyond theends of the hooks where they join into the base of the anchor, which maybe a tube shaped part as discussed above, thereby making the base moreflexible as well. In some examples the slits may be cut as a singlelaser track. Circular openings can be added to the ends of such a cut toprevent high strain points.

In one example the anchor is cut from tubing made of an elastic metal,such as nitinol. Laser cutting may be used. This can involve cuttingtines as discussed above, which can be heat set into curves. The anchormay be heat treated and/or electropolished. Chamfered edges may beintroduced to the anchor on certain parts before the anchor iselectropolished. The openings could contain a barbed or wave profilealong edges of the openings, e.g. along edges of slits. Where slits areused the slotted hooks can be heat set in a configuration where theyhave increased distance when deployed. A barbed profile can then beconcealed when the pins are straight (barbs are facing towards oneanother). With this example, when the anchor comes to a non-constrainedconfiguration then the slits move apart and the barb profile is engaged.

In various aspects the invention extends to the use of the catheterdevices and the anchors described above, and in particular to the use ofthose devices during a procedure for implanting an artificial chordaeline into the heart. Further, the invention extends to the manufactureof the catheter devices and the anchors described above, including thevarious method steps discussed above such as laser cutting from tubes.For any of the anchors, or other laser cut parts discussed hereinchamfered edges may be introduced before the laser cut part (e.g.anchor) is electropolished.

Viewed from a eighth aspect, the invention provides a method of use ofthe catheter device of the second aspect for implanting both of aleaflet anchor and a papillary anchor into the heart during a procedurefor implanting an artificial chordae line that extends between theleaflet anchor and the papillary anchor, wherein the method comprises:deployment of the leaflet anchor into the leaflet using the leafletanchor deployment mechanism; angling the flexible joint in order tobring the papillary anchor deployment mechanism into close proximitywith the papillary muscle (optionally, alternatively or additionally,extending the joint if it is extendable); and deployment of thepapillary anchor into the papillary muscle using the papillary anchordeployment mechanism. This method may include use of a device with anyof the other features discussed above with reference to any of thevarious device aspects, and/or method features as discussed below. Themethod may include testing the connection of the leaflet anchor prior todeployment of the papillary anchor, such as via testing as discussedabove.

Viewed from a ninth aspect, the invention provides a method of use ofthe catheter device of the sixth aspect for implanting a leaflet anchorinto the heart during a procedure for implanting an artificial chordaeline, the method comprising: deployment of the leaflet anchor into theleaflet using the leaflet anchor deployment mechanism with the ejectorunit initially remaining in its first configuration; and later movementof the ejector unit into the second configuration to thereby release theleaflet anchor. The method may advantageously include testing theconnection of the leaflet anchor before moving the ejector unit from thefirst configuration to the second configuration, such as via testing asdiscussed above. The method may include, if the connection of theleaflet anchor is found to be inadequate, keeping the ejector unit inthe first configuration, withdrawing the leaflet anchor into the leafletanchor deployment mechanism using the ejector unit and laterre-deploying the leaflet anchor using the leaflet anchor deploymentmechanism before testing the connection again. This can be repeateduntil an adequate connection is achieved, at which point the ejectorunit should be moved from to the second configuration to release theleaflet anchor. This method may include use of a device with any of theother features discussed above with reference to any of the variousdevice aspects, and/or method features as discussed in relation to thesecond or eighth aspect above, or the other aspects below.

Viewed from a tenth aspect, the invention provides a method of use ofthe catheter device of the first aspect for repair of the heart byimplanting an artificial chordae line, the method comprising: moving thesecond gripper arm away from the main body of the catheter device;moving the first gripper arm away from the main body of the catheterdevice; at least one of: rotating the first gripper arm to bring it intocontact with the second gripper arm to thereby grasp the leaflet at apoint spaced apart from the main body of the catheter device; rotatingthe first gripper arm to bring it into contact with the second gripperarm to thereby restrain the leaflet before rotating the gripper arm tograsp the leaflet between the first gripper arm and the main body of thecatheter device; and pushing the leaflet anchor out of the leafletanchor tube to pierce the leaflet and form the leaflet anchor into anunfolded configuration so that hooked formations of the leaflet anchorsecure the leaflet anchor in the leaflet. This method may include use ofa device with any of the other features discussed above with referenceto any of the various device aspects, and/or method features asdiscussed in the method aspects herein.

Viewed from an eleventh aspect the invention provides a method of use ofthe anchor of the seventh aspect for affixing an artificial chordae lineto the heart, the method comprising using an anchor deployment device toimplant the anchor into the tissue of the heart. The anchor may be usedas a papillary anchor with the method hence including the use of apapillary anchor deployment mechanism. Alternatively, the anchor may beused as a leaflet anchor with the method hence including the use of aleaflet anchor deployment mechanism. This method may include use of adevice with any of the other features discussed above with reference toany of the various device aspects, and/or method features as discussedin the method aspects herein. The method may include testing theconnection of the anchor to the tissue of the heart, such as via testingas discussed above.

Viewed from a twelfth aspect the invention provides a method ofmanufacture of the catheter device of the second aspect, the methodcomprising forming the flexible and optionally extendable joint viacutting of an elastic metal tube. Optionally the same elastic metal tubeis also used to form the distal and proximal parts of the two-part bodysection, which are hence integrally formed with the flexible joint. Anitinol tube may be used and/or the cutting step may use laser cutting.The laser cut tube may be electropolished after cutting in order toremove any sharp edges.

It is considered to offer particular benefits to be able to form thedevice of the second aspect using the method of the twelfth aspect,although it should be noted that other manufacturing methods may be usedas discussed above. The method of the twelfth aspect may includeproviding the catheter device with any of the features discussed abovewith reference to the various device aspects.

Viewed from a thirteenth aspect the invention provides a method ofmanufacture of the ejector unit for the catheter device of the sixthaspect, the method comprising: forming tines into an elastic metal tubevia cutting; and deforming the end of the tines with heat setting inorder to form a hooked configuration. The ejector unit may be providedwith features as discussed above in connection with optional features ofthe sixth aspect. The manufacturing method may include providing acatheter device as in the sixth aspect and inserting the ejector unitinto the catheter device along with a leaflet anchor. A nitinol tube maybe used and/or the cutting step may use laser cutting. The laser cuttube may be electropolished after cutting in order to remove any sharpedges.

Viewed from a fourteenth aspect the invention provides a method ofmanufacture of the catheter device of the first aspect, the methodcomprising forming a hinge of the first gripper arm integrally with themain body of the catheter device via cutting of an elastic metal tube.The method may optionally include forming the entirety of the firstgripper arm, including the hinge, integrally with the main body. It isconsidered to offer particular benefits to be able to form the device ofthe first aspect in this way, although it should be noted that othermanufacturing methods may be used as discussed above. A nitinol tube maybe used and/or the cutting step may use laser cutting. The laser cuttube may be electropolished after cutting in order to remove any sharpedges. The method of the twelfth aspect may include providing thecatheter device with any of the features discussed above with referenceto the various device aspects. This method may be combined with themethod of the twelfth aspect in order to form a single unitary bodysection with the hinge of the first gripper arm (and optionally also theremainder of the first gripper arm) formed in the same integral sectionas the two-part housing section with the distal part and proximal partconnected by the flexible joint.

Viewed from a fifteenth aspect the invention provides a method ofmanufacture of the anchor of the seventh aspect, the method comprising:forming tines into an elastic metal tube via cutting; forming openingsin the tines; and deforming the tines into hooked forms and heat settingthem to form the hooks with openings. The anchor may be provided withfeatures as discussed above in connection with optional features of theseventh aspect. It is considered to offer particular benefits to be ableto form the anchor of the seventh aspect in this way, although it shouldbe noted that other manufacturing methods may be used as discussedabove. A nitinol tube may be used and/or the cutting step may use lasercutting. The laser cut tube may be electropolished after cutting inorder to remove any sharp edges.

In any of the aspects discussed above, the leaflet anchor may be formedfrom an elastic material and to be arranged so that it assumes anunfolded configuration when no force is applied, and to be able todeform elastically into a folded configuration, for example whenconstrained within the leaflet anchor tube. The leaflet anchor may bemade of a shape memory material, for example a shape memory metal.Nitinol may be used for the leaflet anchor. In some example embodimentsthe leaflet anchor is made from a laser cut nitinol tube. The anchor maybe subject to electropolishing after laser cutting in order to removeundesirably rough or sharp edges. The edges may be chamfered beforeelectropolishing in order to introduce greater curvature, e.g. wheresutures or wires may bear against the edges when the anchor is in use.

One exemplary form for the leaflet anchor of any of the above aspects isa grapple hook shape, when it is in the unfolded configuration. Theleaflet anchor may hence comprise a straight central shaft with a numberof hooks spaced apart radially around the shaft. When in the foldedconfiguration the hooks would be straightened out. The leaflet anchormay conveniently be manufactured by cutting a tube to form sharpenedtines at one end, which are then bent into the hooks, with the other endof the tube forming the shaft. The shaft may have a diameter that isrelatively small compared to the radial extent of the hooks in theunfolded configuration. For example the shaft may have a diameter of 30%or less of the maximum radial extent of the hooks, for example 20% orless. In one example the shaft is 1-2 mm in diameter and the hooksextend over a diameter of about 5-25 mm. If a shape memory material suchas nitinol is used then the tines may be bent and heat set into thegrappling hook shape after laser cutting of the nitinol tube.

The leaflet anchor may be provided with one or more sheaths ofbiocompatible material around the hooks, for example a sheath of ePFTE.This material may be placed around the majority of the hooks leaving theends of the hooks free so as not to impede piercing of body tissue. Asingle sheath may be used to provide a covering for two hooks by meansof cut outs allowing the sheath to extend across the centre of theanchor and be threaded onto two hooks at two sides of the anchor. Such asheath might be a tube with an opening, or multiple openings, along oneside of the tube where it bridges the centre of the anchor, thusallowing the two hooks to be threaded into the opening(s) at two sidesof the centre. A method of manufacture of such a hook with a sheath maycomprise inserting the hooks of the anchor into one or more sheaths,e.g. by threading the hook into an ePTFE tube or tubes. An added benefitwith this approach is that the artificial chordae line may be threadedaround the sheath, locking it in place in the centre of the anchor. Thisis not possible if the hooks are threaded with individual tubes and/orsheaths, and it allows for easier routine of the line.

Viewed from a sixteenth aspect, the invention provides an anchor forimplantation in body tissue to hold a line, the anchor comprising: anelastic material formed to have an unfolded configuration for placementwithin the body tissue, and a folded configuration for use prior todeployment of the anchor and arranged to permit placement of the anchorinto an anchor tube prior to deployment; wherein the anchor is arrangedto be elastically deformed into the folded configuration by applicationof a constraining force, and will return to the unfolded configurationwhen no constraining force is applied; wherein when the anchor is in theunfolded configuration the anchor has an elongate configurationcomprising two anchor pins extending in opposite directions with oneeither side of a centre of the anchor, whilst when the anchor is in thefolded configuration the two pins both extend in the same direction; andwherein ends of the pins are arranged to pierce the body tissue.

It has been found that in some instances some types of body tissue, suchas the leaflet(s) of the heart, do not heal as effectively as othertypes of body tissue, such as the heart wall. Thus, it is beneficial insome instances to provide an anchor designed to result in minimal injuryto the body. Such an atraumatic anchor can provide advantages,especially if the form of the anchor allows the body tissue to easilygrow around it. The elongate form of the proposed anchor can allow forminimal damage to thin body tissues such as the leaflet, whilst alsoallowing for close contact with the tissue after implantation so thattissue can grow around the anchor. Close contact and growth of tissuearound the anchor means that rotation and translation of the anchor isprevented once it is implanted. When used as a leaflet anchor the endsof the anchor pins can pierce the leaflet during implantation and passthrough the leaflet, and when the anchor assumes the unfoldedconfiguration the elongate form will be threaded through the leafletwith outer parts of the two pins on one side of the leaflet, and thecentre of the anchor as well as central parts of the two pins on theopposite side of the leaflet. This allows for minimal trauma to theleaflet with a relatively large surface area of the pin placed againstthe surfaces of the leaflet after implantation. In addition the anchormay have a thin profile, which is more ideal for implantation into athin body such as a leaflet.

It will be appreciated that the anchor of this aspect may be used as aleaflet anchor or for other forms of tissue, such as for a papillaryanchor, although in the examples herein it is used as a leaflet anchoras discussed below. The anchor may be included within an anchordeployment mechanism, which in turn may be a part of a catheter device.In particular, the anchor may be provided within a leaflet anchordeployment mechanism, such as in a catheter device for placement of anartificial chordae line into the heart, including catheter devices ofthe type discussed above with reference to the various device aspects.Thus, the anchor tube may be the leaflet anchor deployment tube of thedevices discussed above.

The unfolded configuration is an elongate configuration comprising twoanchor pins extending in opposite directions with one either side of acentre of the anchor, and the elongate form may be a generally straightshape. In the folded configuration the two pins both extend in the samedirection and in some examples the folded configuration has a U-shape.The ends of the pins are arranged to pierce the body tissue and thus theends may be sharp sections, with a pointed shape and/or sharpened edges.

In one example the anchor is formed from an elongate plate with a curveacross its width. The elongate plate may for example have a length towidth ratio of at least 5:1, for example a length to width ratio ofbetween 5:1 and 15:1. Typically the length of the anchor (in theunfolded configuration) may be 5-10 mm. The curvature across the widthis used to increase the stiffness of the anchor and hence to increasethe force with which the anchor pushes back toward the unfoldedconfiguration. Once the anchor is folded the curvature becomes flat,which means that further folding needs only a relatively small force.The original curvature impacts on the amount of elastic strain in theanchor material when it is flat, which in turn affects the elasticforces that urge the anchor to return to the unfolded configuration. Atypical curvature might be in the range 1-5 mm radius for a thickness ofthe plate in the range 0.05 to 0.5 mm. To obtain a curved plate theanchor may be formed from a flat plate that is deformed and heat set.Alternatively a curved plate could be provided as a section cut from atube of the required curvature. The latter approach can involve fewermanufacturing steps since pre-existing tubular sections can be used toprovide the required curvature.

In an alternative example, the anchor is formed from a tubular body witha weakened section at the centre of its length to allow for elasticbending of the tube. In this case the ends of the pins may be providedby diagonal cuts across the tube, leaving sharp tips similar to those onhollow needles. The weakened section at the centre of the tube lengthcan be provided by cutting one or more openings into the tube. With thisexample the ratio of the length to the diameter of the tubular bodymight be at least 5:1, for example a length to width ratio of between5:1 and 15:1. Typically the length of the anchor (in the unfoldedconfiguration) may be 5-10 mm. The thickness of walls of the tube may be0.05-0.5 mm.

The anchor may be formed of an elastic metal, for example a shape memorymetal such as Nitinol.

The anchor may include cut-outs or edges with shapes used to change thebending properties and/or to enhance tissue growth and/or preventhorizontal movement once placed. For example, slits, holes, barbs,recesses or ridges may be used. There may be features present to preventside-ways or rotational movement of the anchor after it has beenimplanted. Thus, ridges or other features as listed above might beprovided along the length of the anchor pins in order to inhibitsideways movement of the pins when in contact with body tissue. Theremay be openings in the pins with features as discussed above inconnection with the openings in the hooks of the anchors of the sixthaspect. Such openings may be formed as discussed above in relation tothe method of manufacturing the anchors of the seventh aspect.

The anchor may have a coating or covering for promoting growth in thebody tissue, and in particular for improved ingrowth in heart tissue.The coating or covering may cover the main part of the anchor but leavethe ends of the pins exposed. One example material for such a coating orcovering is ePTFE. Another possibility is Dacron. Other biocompatiblematerials may be used. The anchor may be covered in a sheath ofbiocompatible material, such as an ePTFE sheath, this could be assembledby threading the anchor through a tube of material with the anchor inthe unfolded configuration. A fabric or woven material may be used.ePTFE has excellent ingrowth in heart tissue, and is well proven incardiac surgery. An anchor covered with ePTFE is likely to grow into theleaflet further increasing the holding strength and in addition reducingthe chance of embolization.

Where a sheath of material is used this may be sutured to the anchor,for example by threading suture through holes in the sheath and theanchor. This may help to prevent the cover to be inverted or pulled intoa “lump”, as well as reducing chance of embolization if the anchorfractures, since the sheath and suturing will hold parts of a brokenanchor together.

There may be an artificial chordae line attached to the anchor. The linemay be glued, knotted or threaded multiple times through the anchor tobe attached, the line may also be attached in two locations with a loopor similar to distribute forces, and prevent horizontal movement ifpulled at an angle. One or more injection moulded part(s) may be used toreduce wear between the line and the metal parts of the anchor in theattachment point(s) of the artificial chordae line. The benefit of usingtwo attachment points with injection moulded protection around the lineentry point is that the line entry points may prevents horizontalmovement of the anchor once placed.

As noted above, the anchor may be included within an anchor deploymentmechanism, which in turn may be a part of a catheter device. In oneexample, this is a catheter device for implanting an anchor during aprocedure for implanting an artificial chordae line into the heart, thecatheter device comprising: the anchor, an anchor deployment mechanismfor deploying the anchor, and an ejector unit for releasably graspingthe anchor. The ejector unit may releasably attach to the anchor at thecentre of the anchor. In some examples the anchor deployment mechanismallows for retraction and repositioning of the anchor after deploymentof the anchor into the body tissue via the ejector unit, wherein theejector unit has a grasping device with a first configuration arrangedto permit deployment of the anchor into the body tissue withoutdisengagement of the anchor from the ejector unit, and a secondconfiguration in which the anchor is reversibly released from theejector unit; wherein in the first configuration the grasping device ofthe ejector unit grasps the centre of the anchor, whilst the pins of theanchor are unimpeded by the grasping device to enable it to be implantedin the body tissue; and wherein in the second configuration the graspingdevice of the ejector unit is disengaged from the anchor.

It will be appreciated that the ejector unit of this example can take aform similar to the ejector unit described above in relation to thefourth aspect. Thus, the structure and function of the ejector unit maybe as discussed above, and the ejector unit as well as the deploymentmechanism may interact as discussed above. The deployment mechanism mayinclude an anchor tube as with the leaflet anchor tube described above.The anchor may be a leaflet anchor.

The anchor may be provided with tabs or recesses either side of thewidth of the anchor at its centre in order to allow for the graspingdevice of the ejector unit to better engage with the anchor, for examplevia corresponding hooks or openings to engage with tabs or hooks toengage with recesses.

Viewed from a seventeenth aspect, the invention provides a method formanufacture of an anchor according to the sixteenth aspect, the methodcomprising: forming the anchor from an elastic material, with the anchorin the unfolded configuration. The method may include forming the anchoras a curved plate or from a tubular body as discussed above. When theanchor is formed from a curved plate then the method may comprisecutting the curved plate out from a tube of the same radius as therequired curve. This is has been found to provide a straightforward wayto manufacture the required curved profile for the anchor.Alternatively, the anchor may be cut from a flat sheet and then heat setto a curved shape. The method may include providing a sheath ofbiocompatible material around the elastic material of the anchor, forexample a sheath of ePFTE. The method may comprise inserting the pins ofthe anchor into a sheath, e.g. threading the anchor into an ePTFE tube.This may be done by passing one end of a first pin through the sheathand drawing the elongate form of the anchor through the sheath. Thesheath may enclose the centre of the anchor and the majority or entiretyof the two pins, leaving the ends of the pins exposed. Alternatively,the sheath may enclose the majority of the two pins, with the ends ofthe pins exposed and with an opening at the centre to allow for bendingof the anchor with lesser restriction from the sheath. This shape ofsheath is similar to that discussed above for a grapple hook shapedanchor.

Viewed from an eighteenth aspect, the invention provides a method of useof the anchor of the sixteenth aspect for affixing an artificial chordaeline to the heart, the method comprising using an anchor deploymentdevice to implant the anchor into the tissue of the heart. The anchormay be used as a papillary anchor with the method hence including theuse of a papillary anchor deployment mechanism. Alternatively, theanchor may be used as a leaflet anchor with the method hence includingthe use of a leaflet anchor deployment mechanism. This method mayinclude use of a device with any of the other features discussed abovewith reference to any of the various device aspects, and/or methodfeatures as discussed above in the other method aspects. The method mayinclude testing the connection of the anchor to the tissue of the heart,such as via testing as discussed above.

In relation to any of the aspects discussed above, it is advantageous ifthe leaflet anchor can be placed into the leaflet from beneath, i.e.from the side where the papillary muscle is located, so that the newartificial chordae line may pull the leaflet downward. However, the mostconvenient route to access the heart involves the catheter entering fromabove the leaflet. To facilitate the placement of the leaflet anchorfrom beneath, the catheter device of any of the above aspects may bearranged so that the open end of a leaflet anchor tube is at a proximalend of the gripper device (the ‘upper’ end when in the heart in theabove defined orientation) and the leaflet anchor can be pushed out ofthe tube moving from the distal end of the catheter device toward theproximal end. The catheter device may include a U-shaped rod fordeployment of the leaflet anchor. This may be a U-shaped piece at theend of a wire that is used to actuate the leaflet anchor. Alternativelyit may be a U-shaped rod attached to a separate wire at one end of theU-shape. In either arrangement the free end of the U-shape abuts the endof the leaflet anchor and is arranged to push the anchor toward theproximal end of the catheter device when the wire is pulled. TheU-shaped rod should be sufficiently stiff to hold its shape when pulledwith force applied to the anchor. A ball may be placed at the free endof the U-shaped rod to allow it to best engage with the leaflet anchor(or with the ejector unit, where present). In this way the leaflet canbe pierced from beneath.

When the leaflet anchor tube is in the gripper arm, such as the firstgripper arm, then the U-shaped rod may extend into the gripper arm. Inthis case the U-shaped rod needs to be sufficiently elastic to bend whenthe gripper arm is opened and closed. The U-shaped rod may have aflexible section, for example a section of narrowed cross-section, foraiding the bending motion. The U-shaped rod may also or alternatively bemade of a suitably elastic material, which could be nitinol.Advantageously, the elasticity of the U-shaped rod may act as a springto return the gripper arm to the closed position.

Alternatively the U-rod wire may be made so that no bending is necessarywhile the gripper opens, if the end of the U-rod is small enough to nottouch the walls of the leaflet anchor tube while the gripper rotates, itdoes not have to bend while the gripper opens. This advantageouslyallows for a greater operation angle not limited by a requirement forallowing for the U-rod to deflect.

The catheter device of any of the above aspects may include anartificial chordae line attached to the leaflet anchor. A hole or eyemay be provided in the leaflet anchor for attachment of the artificialchordae line. In some example embodiments the chord is joined in thecatheter device to a wire that enables it to be pulled or pushed. Theuse of such a wire allows for shortening and lengthening adjustments tothe chord. The artificial chordae line may be a Gore-Tex® suture orother appropriate biocompatible material, such as a thin nitinol wire,an ultra-high-molecular-weight polyethylene (UHMWPE) wire, or acomposite wire comprising a tough core such as nitinol or high strengthsuture and an outer coating such as PTFE or ePTFE. The artificialchordae line may comprise an ePTFE suture tube, which may be threadedwith a Dyneema core. This Dyneema core may be the same suture that isthreaded through the leaflet anchor as mentioned above. TheePTFE-Dyneema tube construction of the artificial chorda line may inaddition be coupled to a wire (preferably nitinol) in the opposite endof the leaflet anchor, for example by threading the nitinol wire intothe ePTFE tube together with the Dyneema core. The ePTFE tube and theDyneema wire can then be attached by crimping, gluing or similar methodsonto the nitinol wire to allow adjustment of the new artificial chordaeline with minimal friction. Such adjustment may be done through anadjustment catheter. In some example embodiments the catheter devicealso holds a papillary anchor for attachment to the papillary muscle.The artificial chordae line may extend from the leaflet anchor to thepapillary anchor. In some embodiments the artificial chordae line joinsthe two anchors together directly, with no intervening clip as in WO2008/101113. This means that the artificial chordae line can moreclosely emulate the natural chords, and so the repair to the heart ismore effective.

The adjustment catheter may have stainless steel wire within in itswalls, to allow it to exert a pulling force strong enough to retract thepapillary anchor. The adjustment catheter may further have one or moresmall lumens in the wall that allows for actuation of the adjustment andcutting mechanism. Stainless steel tipping may be attached in one orboth end of the shaft, and this can be mechanically bonded by forexample welding, knots, glue or material reflow to the shaft itself andthe stainless steel wires inside the walls of the shaft, alternativelythe stainless steel wires in the wall of the shaft may be looped arounda feature in the stainless steel tipping (which may be connected to ormay form a part of the adjustment housing such as the piston housing ofan anchor holder of the type discussed above). The stainless steeltipping may be laser welded to the papillary anchor cutting andadjustment mechanism.

With any of the above aspects the papillary anchor may be formed from anelastic material and may be arranged so that it assumes an unfoldedposition when no force is applied, and to be able to deform elasticallyinto a folded position, for example when constrained within a papillaryanchor housing of the catheter device. The device may be arranged sothat the papillary anchor can be pushed out of the papillary anchorhousing in order to pierce the papillary muscle with the hooks and tosecurely engage the anchor with the muscle as the hooks curl into theunfolded position. The papillary anchor may be made of a shape memorymaterial, for example a shape memory metal. Nitinol is a preferredmaterial for the papillary anchor. In one preferred embodiment thepapillary anchor is made from a laser cut nitinol tube.

The papillary anchor may include a number of hooks for piercing andengaging with the tissue of the papillary muscle. A grappling hook shapeis possible, similar to the leaflet anchor, but the preferred design forthe papillary anchor uses a slightly wider tube section relative to theextent of the hooks. Thus in some example embodiments the papillaryanchor includes a tube section with a number of hooks extending from oneend of the tube, wherein the hooks extend across a diameter that is lessthan three times the diameter of the tube, for example about twice thediameter of the tube.

Similarly to the leaflet anchor, the papillary anchor may convenientlybe manufactured by cutting a tube to form sharpened tines at one end,which are then bent into the hooks, with the other end of the tubeforming the body of the anchor. If a shape memory material such asnitinol is used then the tines may be bent and heat set into the hookshape after laser cutting of the nitinol tube. The anchor may be subjectto electropolishing after laser cutting in order to remove undesirablyrough or sharp edges.

In any of the above aspects and optional features the papillary anchor,where present, may be provided with a mechanism for releasably clampingthe artificial chordae line. In one example, the papillary anchor isprovided with a locking mechanism that clamps the chord when no force isapplied, and that can be elastically deformed to release the chord foradjustment of the length of the chord during implantation thereof. Thismeans that after the leaflet anchor and the papillary anchor areimplanted then the new chord can be tensioned appropriately, whilstmonitoring heart function, to ensure that the repair is effective, andthen the chord can be clamped by releasing the force on the anchor.After implantation, since the locking mechanism clamps the chord when noforce is applied, then the chord will be held between the leaflet andthe papillary muscle with the right tension. The papillary anchor may belaser cut before being electropolished. The introduction of chamfers tothe edges of the anchor may reduce friction of the chordae line bearingagainst its edges during adjustment of its length.

The locking mechanism may comprise a resiliently deformable lockingsegment formed in a wall of the anchor and divided from the wall by oneor more slit(s). The anchor may be arranged so that when no forced isapplied then the slits are closed with no gap or a relatively narrow gapin order to clamp the line, whereas when a suitable force is applied tothe locking segment and/or wall then the locking segment and/or the wallwill elastically deform to widen the opening provided by the slit(s) sothat the line is released. The anchor may have a tubular body section,in which case the locking segment may be formed in the wall of the tube.The locking segment may be a band with parallel slits on two sides, suchthat the band can be pulled out of plane with the wall by application ofa force in order to open up the slits.

Such a locking segment can be held open by sliding a holder into theslit(s). The anchor may be used in a system comprising an anchor housingfor holding the anchor in the unfolded position prior to implantation, aholder for holding the locking mechanism open, a line, and the anchorattached to the line. The holder may comprise a Z-shaped fork withprongs for insertion into the slit(s). The use of a Z-shaped fork canallow for the path of the suture within the anchor housing to have asuitable curve.

The use of electropolishing to mitigate the risk of fraying and/orcutting, and to provide an anchor able to clamp firmly without cuttingis considered important. For the papillary anchor, friction over theedges of the anchor experienced by an artificial chordae line having itslength adjusted may be reduced due to laser cutting chamfering the edgesbefore electropolishing. Thus, for methods comprising laser cutting atube, and for devices including a laser cut tube element such as a lasercut anchor, then electropolishing is advantageously used after the lasercutting.

Certain example embodiments of the invention will now be described byway of example only and with reference to the accompanying drawings inwhich:

FIG. 1 illustrates the procedure for insertion of a catheter devicethrough a mitral valve;

FIGS. 2 to 6 show the action of a mechanical gripping mechanism usingtwo gripper arms;

FIG. 7 illustrates gripping of a leaflet of the mitral valve with onegripper arm;

FIGS. 8 to 12 show deployment of a leaflet anchor in a device using anejector device;

FIG. 13 shows a close up view of the valve during placement of a leafletanchor, which is coupled to an artificial chordae line;

FIG. 14 shows movement of the distal end of the catheter device to thepapillary muscle for placement of a papillary anchor;

FIG. 15 illustrates withdrawal of a treatment catheter part of thedevice and adjustment of the chord length with an optional adjustmentcatheter;

FIGS. 16 and 17 show an example of a hook for an anchor which isthreaded with a suture;

FIGS. 18 and 19 show the folded and unfolded configuration of an exampleof a papillary anchor;

FIG. 20 is a cross-section through a lower (distal) part of the mainbody of the catheter device showing how the main parts fit inside apapillary anchor deployment mechanism;

FIG. 21 shows an example arrangement for the routing of the artificialchordae line and other lines within the papillary anchor deploymentmechanism of FIG. 20;

FIG. 22 is a cross-section of an example with the papillary anchordeployment mechanism of FIG. 20 and a gripping mechanism as in FIGS. 2to 6, including one possible routing of the artificial chordae linebetween the papillary anchor and the first gripper arm

FIG. 23 is a cross-section of a leaflet anchor deployment mechanismusing a leaflet anchor with a straight form when unfolded;

FIG. 24 shows the leaflet anchor and ejector unit of FIG. 23 with theleaflet anchor tube omitted;

FIG. 25 shows the leaflet anchor of FIG. 23 after deployment;

FIG. 26 illustrates the leaflet anchor of FIG. 23 with a covering aboutthe anchor;

FIGS. 27 and 28 show an alternative form for a straight anchor in theunfolded and folded configurations;

FIG. 29 shows a catheter device similar to that of FIGS. 4 to 6,modified via the use of a sliding chordae holder;

FIG. 30 shows another example of an adjustment and cutting cathetertogether with the papillary anchor;

FIG. 31 is a side view of another example of a two-part housing sectionfor the catheter device;

FIG. 32 shows the two-part housing section of FIG. 32 in a differentview;

FIG. 33 shows another example of a catheter device with a cross-sectionthrough a housing section thereof;

FIG. 34 shows a distal part of the housing section of the device of FIG.33;

FIG. 35 to include is a perspective view, a side view, and across-section of an anchor and adjustment housing of the device of FIG.33, with the housing section omitted to show detail of the anchor in thestowed position;

FIG. 38 shows a cross-section similar to FIG. 37 with the anchor in thedeployed, unfolded state;

FIGS. 39 and 40 show further details of the adjustment housing of FIGS.35-38;

FIGS. 41 and 42 show an internal cam of the adjustment housing;

FIG. 43 is an exploded view of various parts of the catheter device ofFIG. 33;

FIG. 44 is a side view of the anchor and adjustment housing with theanchor in the deployed, unfolded state;

FIG. 45 shows a non-circular shape in the distal part of the deviceincluding an engagement funnel;

FIG. 46 is a side view of the catheter device displaying how a hingepullwire may be arranged;

FIGS. 47A and 47B show exemplary self-locking knots which can be used toattach a suture and/or artificial chord to the leaflet anchor;

FIGS. 48A and 48B show two different perspectives of the piston wedgeengaged with the locking segment, the piston wedge not in contact withan internal wall of the anchor;

FIG. 49A shows an anchor having tips that extend outward in a foldedposition, while FIG. 49B shows an anchor having tips that extend inwardin a folded position;

FIG. 50A shows the anchor of FIG. 49A in an unfolded position, whileFIG. 50B shows the anchor of FIG. 49B in an unfolded position;

FIG. 51 shows a device handle capable of operating the catheter device;

FIG. 52A shows the two-arm gripper device, with the two gripper arms inan open configuration, while FIG. 52B shows the two gripper arms of thegripper device closed together;

FIGS. 53A and 54A show the gripper device passing through a modelleaflet valve with the leaflet motion suppressor above the leaflet andthe first gripper arm grasping from below (not shown);

FIGS. 53B and 54B show the gripper device passing under the leafletvalve with the leaflet motion suppressor still above the leaflet and thefirst gripper arm grasping from below (not shown);

FIGS. 53C and 54C show the gripper device grasping the leaflet, with theleaflet motion suppressor grasping the leaflet from above and the secondarm grasping from below (not shown); and

FIGS. 55A, 55B and 55C show alternative arrangements suitable for theleaflet motion suppressor.

The catheter devices presented here are proposed for non-surgical(endovascular) insertion of mitral chords to address mitralregurgitation caused by prolapse of a leaflet 12 of the valve. TheFigures show different forms of catheter device 2 for this purpose, butit will be understood that the general principles are the same for eachdevice in terms of implantation of a leaflet anchor 10 and a papillaryanchor 9 in order to insert one or more artificial chordae lines 14 intothe heart. The artificial chordae line(s) 14 are fixed to the prolapsingleaflet 12 and to the papillary muscle 26, thereby recreating a normalanatomy. A single catheter device 2 is used to place both a leafletanchor 10 and a papillary anchor 9. The length of the chord 14 can beadjusted, again using the same catheter device 2, to eliminate themitral regurgitation. Thus, the new device enables a single minimallyinvasive endovascular procedure to be used to repair the mitral valve,providing significant advantages compared to earlier systems requiringmore invasive procedures and/or multiple operations.

It should be noted that although an endovascular approach is preferredand the device is hence capable of using this approach, the device couldof course be used in different procedures, including more invasiveprocedures. Many of the advantages will remain, and it could bebeneficial to use this device in situations where a more invasiveprocedure is merited. In addition, it is contemplated that, as discussedabove, aspects of the design of the papillary anchor 9 could be used foran anchor for other purposes and this disclosure is not intended to belimited in this regard.

The catheter device 2 described in the following can be used to insertmitral chords through the venous system, starting in the femoral vein inthe groin. A catheter is advanced to the right atrium. Approach to theleft atrium is then gained by a so-called transseptal puncturewhereafter a larger guidance catheter is advanced into the left atrium.The catheter device 2 for the heart repair is then introduced throughthe guiding catheter and into the left atrium.

X-ray and ultrasound guidance is used to position the device and, asexplained in more detail below, the mitral leaflet 12 is grabbed and anew artificial chordae line 14 is attached using a self-expandableleaflet anchor 10. The artificial chordae line 14 is then attached tothe papillary muscle 26, using a, papillary anchor 9. Advantageously,the catheter device shown in FIGS. 2 to 6, 14 and 20 to 22 can be usedto place the papillary anchor 9 whilst the leaflet 12 is still beinggrasped by the device. The chord length can now be adjusted to eliminateany mitral regurgitation. Excess chord is then cut and all catheters arewithdrawn. Echo and Doppler imaging is used to perform the procedure andmonitor the result. The successful use of this endovascular techniquewill drastically reduce the invasiveness, complications and cost ofmitral valve repair.

More detail on the structure and function of the device is set out belowwith reference to the Figures. The procedure of using one form of thedevice can be summarised as follows:

1) The femoral vein is entered using standard Seldinger technique andthe guiding catheter introduced.

2) The guiding catheter is advanced to the right atrium under x-rayguidance.

3) The left atrium is entered after penetration of the atrial septum,guided by x-ray and transesophageal echo.

4) Correct position of the entrance site in the left atrium is verifiedto assure proper alignment for insertion of the guiding and treatmentcatheters. The entrance hole in the atrial septum is dilated and theguiding catheter is advanced into the left atrium.

5) A treatment catheter device 2 is advanced through the guidingcatheter and positioned in the left atrium above the mitral valve.

6) The prolapsing segment of the mitral leaflet 12 is located withultrasound and the treatment catheter device 2 is advanced into the leftventricle placing a gripper 6 of the treatment catheter device 2 inposition to grip the prolapsing segment. Advantageously, this may use agripper 6 with two gripping arms 30, 32 as discussed in more detailbelow with reference to FIGS. 2 to 6.

7) The prolapsing segment is gripped and after assuring correct positionthe leaflet anchor 10 is pushed through the leaflet 12 allowing it toopen and fix the leaflet 12.

8) The connection of the leaflet anchor 10 may be tested whilst itremains attached to the catheter device 2 via an ejector unit 36 asdiscussed further below with reference to FIGS. 8 to 12, and if theconnection is sufficient then the distal end of catheter is advancedfurther into the left ventricle, advantageously using a flexible andextendable joint 34 as shown in FIGS. 2 to 6 and 14, or using a flexiblejoint as shown in FIGS. 31 and 32 to angle the joint without extension,until the distal end makes contact with the papillary muscle 26 orsurrounding tissue.

9) The papillary anchor 9 is pushed into the papillary muscle 26 areaand out of its housing 8 thereby letting the papillary anchor 9 openinside the papillary muscle 26.

10) If the gripper 6 is still grasping the leaflet 12 then it isreleased, such as by releasing the leaflet anchor 12 from the ejectorunit 36 as discussed below with reference to FIGS. 8 to 12.

11) The length of the artificial chordae line 14 is adjusted untilmitral regurgitation is eliminated.

12) The catheter device 2 is pulled back from the papillary anchor 9,and elimination of mitral regurgitation is again confirmed byechocardiography.

13) The position of the artificial chordae line 14 is locked at thepapillary anchor 9.

14) The excess chordae line 14 is cut.

15) Additional artificial chordae lines may be placed if necessary.

16) The catheter device is fully withdrawn and removed from the vascularsystem.

FIG. 1 shows guide catheter 22 that has been used to steer a catheterdevice 2 to a required position within the heart adjacent extendingthrough the mitral valve and hence being between two leaflets 12. Thecatheter device 2 is composed of four different main parts; a steerablecatheter, a gripper housing 4, a gripper device 6 and a papillary anchorhousing 8, which holds a papillary anchor 9. Advantageously the gripperhousing 4 and the papillary anchor housing 8 may form a proximal part 4and a distal part 8 of a two part housing section with a centralflexible and extendable joint 34 as shown in FIGS. 2 to 6, 14 and 20 to22. Thus, it should be understood that the procedure shown in FIG. 1(and likewise in FIGS. 7, 13 and 15) may use this arrangement for thegripper housing (proximal part) 4 and papillary anchor housing (distalpart) 8. The steerable catheter could be replaced with an alternativearrangement using a steerable sheath about a steerable catheter andflexible tubing within the steerable catheter.

FIG. 1 shows a front view of one example catheter device with thegripper device 6 closed. The gripper device 6 of some arrangements usesa single gripper arm 30 that grips the leaflet 12 against the gripperhousing part 4 as shown in FIG. 7. In other arrangements the gripperdevice 6 uses two gripper arms 30, 32 as shown in FIGS. 2 to 6 in orderto allow the leaflet 12 to be grasped between the two gripper arms 30,32 at a point spaced apart from the main body of the catheter device.The gripper device 6 is a part of a leaflet anchor deployment mechanismfor deploying the leaflet anchor 10 to attach it to the leaflet 12 ofthe heart. The gripper device 6 includes a leaflet anchor tube 38 forhousing the leaflet anchor 10 in a folded configuration prior todeployment. In the example embodiments the leaflet anchor tube 38 is inthe (first) gripper arm 30, as seen in FIGS. 2 and 4, for example. Whenthe gripper device 6 grasps the leaflet 12, the leaflet anchor 10 can bepushed out of the leaflet anchor tube 38 to pierce the leaflet 12 andform the leaflet anchor 10 into an unfolded configuration so that hookedformations 40 of the leaflet anchor 10 secure it in the leaflet 12.

The leaflet anchor 10 is connected to an artificial chordae line 14,which can sit inside a narrow channel that goes along the surface of thefirst gripper arm 30 (as shown in FIGS. 8 to 12, for example) and viathe papillary anchor housing 8 to the papillary anchor 9 (as shown inFIGS. 20 to 22, for example). The channel can be slightly smaller thanthe diameter of the new artificial chordae line 14 and/or have a thinshielding structure (not shown). This makes the artificial chordae line14 sit in place due to a friction fit. The new artificial chordae line14 goes into the papillary anchor housing 8 and through a papillaryanchor locking section, through a locking and cutting piece 18, andthrough Z shaped fork 20. These parts are described in further detailbelow with reference to FIGS. 20 to 22. The new artificial chordae line14 can be attached to a wire which passes back along the catheter allthe way to the outside (to make the adjustment smoother). The wireallows for a shortening of the chord during the procedure, by pulling,or a lengthening of the chord, since the wire can be pushed through thecatheter.

The two-part housing section, with the gripper housing (proximal part) 4and papillary anchor housing (distal part) 8 might be approximately 6-7mm in diameter, and approximately 30 mm in length.

FIGS. 2 to 6 show steps in movement of the gripper mechanism 6 in anexample with two gripper arms 30, 32 as discussed above. This grippermechanism 6 is a part of a housing section that also includes a flexibleand extendable joint allowing the papillary anchor housing 8 (distalpart) to be moved toward the papillary muscle 26 after the leaflet 12has been grabbed by the gripper mechanism 6. In this example, in orderto grasp the leaflet 12, the first gripper arm 30 is rotated to move itsend 42 away from the main body of the catheter device, with thisrotation being enabled via a weakened area 44 of the tubular form of themain body. It can be seen that the leaflet anchor tube 38 sits insidethe first gripper arm 30, with the end of the leaflet anchor tube 38having an opening at the end 42 of the first gripper arm 30. With thefirst gripper arm 30 open, the second gripper arm 32 is free to rotateto move its end 46 outward of the main body. In this example the secondgripper arm 32 rotates around a hinge formed by pins 48 placed in holesin the proximal part 4 of the two-part housing section, but it will beappreciated that a similar final placement of its end 46 may be achievedvia a sliding movement. With the second gripper arm 32 folded outwardthe first gripper arm 30 can close so that the two ends 42, 46 come intocontact at a point spaced apart from the main body of the device. Thisallows the leaflet 12 to be grasped. With the leaflet 12 in place theleaflet anchor 10 can be moved out of the leaflet anchor tube 38 toimplant it, such as via a mechanism with an ejector unit 36 as describedbelow in relation to FIGS. 8 to 12, with the final positioning of theleaflet anchor 10 being similar to that shown in FIG. 13.

FIG. 7 shows an alternative form of gripper mechanism 6 that grasps theleaflet 12 with a single gripper arm that holds it against the gripperhousing 4. This could also use the ejector unit 36 mechanism of FIGS. 8to 12.

A ridged surface on the gripper arm(s) 30, 32 may be provided to help itgrip the leaflet 12. 3D ultrasound and/or other available sources can beused to confirm that the gripper mechanism 6 has grasped the correctpart of the leaflet 12.

The gripper mechanism 6 can be opened and closed as many times as neededto grasp the right part of the leaflet 12. The opening and closing maybe facilitated by a system allowing for one wire to pull the grippermechanism 6 open, and one to pull it closed. Different arrangements ofwires and/or rods may be used to control the example with two gripperarms 30, 32, as discussed above. Once the position of the grippermechanism 6 is confirmed then the leaflet anchor 10 can be pushed out ofthe end of the leaflet anchor tube 38, such as by pulling a wire in theother end of the catheter. FIG. 13 shows a close up view of the leafletanchor 10 placed in the leaflet 12 with the hooked formations 40engaging with the leaflet 12.

As noted above, an ejector unit 36 may be used as shown in FIGS. 8 to12. With the use of the ejector unit 36 the leaflet anchor deploymentmechanism allows for retraction and repositioning of the leaflet anchor10 after deployment of the anchor 10 into the leaflet 12. This isachieved via the ejector unit 36, which includes a grasping device 50with a first configuration, as shown in FIG. 8 and FIG. 9 and a secondconfiguration as shown in FIG. 10 and FIG. 11.

In the first configuration the grasping device arranged to permitdeployment of the leaflet anchor 10 into the leaflet 12 withoutdisengagement of the leaflet anchor 10 from the ejector unit 36. Thus,the grasping device 50, which in this example comprises two grapplinghooks 50 as shown, grips the leaflet anchor 10 and can advance along theleaflet anchor tube 38 from the fully stowed position as in FIG. 8, to aposition in which the anchor 10 is deployed as shown in FIG. 9, withoutreleasing the anchor 10. The grappling hooks 50 are held to the leafletanchor 10 as they are constrained within the leaflet anchor tube 38. Theejector unit 36 is hence arranged so that it remains in the firstconfiguration whilst the leaflet anchor 10 is being implanted. With theleaflet anchor 10 implanted the grasping device 50 and ejector unit 36can be used to test the connection of the leaflet anchor 10 to theleaflet 12, for example by a force being applied to the leaflet anchorfrom the ejector unit whilst the grasping device 50 is in the firstconfiguration.

The grasping device 50 moves into the second configuration when theconstraint from the leaflet anchor tube 38 is no longer present, forexample when the grappling hooks 50 move beyond the end of the tube asshown in FIG. 10. Thus, if the connection has been tested and thephysician decides to release the leaflet anchor 10 then they can furtheradvance the ejector unit 36, which will move it into the secondconfiguration. In this second configuration the grasping device 50 ofthe ejector unit 36 is disengaged from the leaflet anchor 10.

If the physician is not satisfied by the connection during the testing(for example, if there is too much movement of the anchor 10 and/or notenough resistance to force on the line) then the leaflet anchor 10 canbe retracted and placed in another location. If the grasping device 50did not change from the first configuration during this test then thelatter procedure may be carried out by reversing the deployment of theejector unit 36 and leaflet anchor 10, for example by drawing thoseparts back into the leaflet anchor deployment mechanism. If the secondconfiguration was used before it was determined that the connection ofthe anchor was not adequate then to retract the anchor 10 the ejectorunit 36 should be first moved back to the first configuration so thatthe grasping device 50 reengages with the leaflet anchor 10, and thenafter that the deployment of the ejector unit 36 and leaflet anchor 12is reversed, for example by drawing those parts back into the leafletanchor tube 38.

A groove 52 is provided in a wall of the leaflet anchor tube 38 forguiding the ejector unit 36. The groove 52 ensures that the ejector unit36 remains a single orientation relative to the tube 38 while it ismoved along the tube. The groove 52 can set maximum limits on the rangeof movement of the ejector unit 36 and thus may prevent it from goingtoo far in either direction, out of or into the leaflet anchor tube 38.The ejector unit 36 has a guide pin 56 for engagement with the groove52. A narrowing 54 in the groove 52 is provided to act as an indicatorto let the operator know when the ejector unit 36 has reached a certainposition. The size of the guide pin 56 and the width of the narrowing 54are set so that engagement of the pin 56 with the narrowing 54 in thegroove 52 will require an increased force before further movement can bemade, thus providing tactile feedback to the operating physician.

The leaflet anchor deployment mechanism of FIGS. 8 to 12 also includes aline pusher 58 for directing the artificial chordae line 14 out of andaway from the leaflet anchor tube 38 during deployment of the anchor 10.The line pusher 58 directs the artificial chordae line away from theleaflet anchor tube 38 so that it can be more readily accessed for latermanipulation, such as for tightening the line 14 or for pulling on theimplanted leaflet anchor 10 for testing of the connection. The linepusher 58 is actuated during the action of deployment of the leafletanchor 10, with this actuation being triggered when the leaflet anchor10 is released from the ejector unit 36. Thus, the line pusher 50 isreleased when the ejector unit 36 withdraws away from the implantedleaflet anchor 10.

In the example shown, the line pusher 58 transitions from a constrainedstate to a non-constrained state and moves radially outward to push theline 14 out, with this radially outward movement being permitted and theline pusher released once a constraint from the leaflet anchor 10 isremoved. The line pusher 58 is an arm that extends axially forward fromthe ejector unit toward the leaflet anchor 10 and radially outward ofthe leaflet anchor tube 38 when the arm is at rest with no forcesapplied. Prior to deployment of the leaflet anchor 10 the arm of theline pusher 58 is bent elastically to place its distal end within theleaflet anchor 10, as shown in FIGS. 8 and 9, so that it is constrainedand cannot move to its radially outward position until the leafletanchor 10 and the ejector unit 36 move apart, as is best shown in FIG.11. As the ejector unit 36 continues to withdraw into the leaflet anchortube 38 the line pusher 58 remains in its unconstrained state with theline pusher 58 as well as the line 14 being pushed out of a slit in theleaflet anchor tube 38, as shown in FIG. 12.

With the leaflet anchor 10 implanted in the leaflet 12 the papillaryanchor housing 8 at the end of the treatment catheter is then placedonto the papillary muscle 26. With the use of a flexible and extendablejoint 34 this may be done as shown in FIG. 14. In this example, theflexible and extendable joint 34 is formed by flexible meanderingsections cut into a tubular form of the main body. Advantageously theflexible and extendable joint 36 is formed integrally with a tubulardistal part 8, which provides the papillary anchor housing 8 and with atubular proximal part 4, which provides the gripper housing 4. Furtheradvantageously the tubular form of the gripper housing 4 may include anintegrally formed gripper arm 30, with a weakened section 44 of the tubeproviding a hinge. The flexible and extendable joint 34 can be extendedby means of wires and/or rods 60 (or via an adjustment catheter 21, thatalso may push out the papillary anchor 9), which may apply a force tostretch elastic elements of the joint 34. This extension is used to movethe papillary anchor 9, within its housing part 8, to place it againstthe papillary muscle 26, or close to it, since the wires/rods along withthe papillary anchor 8 within the distal housing part 8 move with thehousing 8 as the joint 34 extends. This can be due to friction betweenthe papillary anchor 9 (or a papillary anchor push tube) and theinternal surface of the distal part 8 of the housing section. Theposition can be confirmed by 3D ultrasound and/or other availablesources.

When the distal end of the distal part 8 meets the body tissue, and asfurther force is applied the counterforce from the body tissueeventually surpasses the forces holding the papillary anchor 9 in place,at this point tissue is pushed flat below the base of the distal part 8giving a maximal chance of placing all pins 62 of the papillary anchor 9correctly in tissue, and force can be applied to the papillary anchor 9so that the ends of the pins 62 then move beyond the distal end of thedistal part 8 to meet the body tissue. This may be done via additionalforce on the papillary anchor 9 from rods or wires 60 or extending theadjustment catheter 21, or advantageously it may be done through apre-tension on the papillary anchor 9 (or friction between theadjustment catheter 21 and the distal part 8) that is held by frictionwith the distal part until the forces from the body tissue on the distalpart 8 changes the balance of forces with the friction sufficiently sothat the papillary anchor 9 ejects in a way similar to a paper stapler.As the papillary anchor 9 is ejected the pins 62 fold out and form intothe hook shape of the unconstrained papillary anchor 9 to thereby engagewith the body tissue 26. At this point the connection can be pull testedby operator, and/or visually confirmed on x-ray and/or ultrasound. Ifthe connection is not satisfactory, the papillary anchor 9 can be pulledback into the distal part 8 and re-placed to attempt an improvedcoupling of the anchor 9 with the body tissue 26.

FIG. 15 shows the possible next steps. The main part 4, 8 of the deviceis retracted to minimize influence on the moving leaflets 12. Anadjustment catheter 21, which may comprise a Z-shaped fork 20 at itsdistal end as shown in FIGS. 20 to 22, can remain at the papillaryanchor 9. The length of the artificial chordae line 14 can be adjustedwith a wire from the outside. The length is continuously adjusted andthe functioning of the leaflet 12 is monitored. The length of theartificial chordae line 14 can be reduced by pulling the chord wire backthrough the catheter. The length can also be increased by pushing thechord wire, which will slacken the artificial chordae line 14 and allowthe movement of the leaflet 12 to pull it out of the adjustment catheter21. The small size of the adjustment catheter 21 means that the effectof the device on the functioning of the leaflet 12 is minimised. Theright length for the artificial chordae line 14 is confirmed with 3Dultrasound and/or other available sources.

When the correct length is confirmed then the device is disengaged fromthe papillary anchor 9. This process also locks the artificial chordaeline 14 in place and cuts off any excess, which is retained in thecatheter and withdrawn from the body when the catheter is removed. FIGS.20 to 22 include more detail of the Z-shaped fork 20 and the cuttingpiece 18, as discussed below. The Z-shaped fork is used to hold open alocking segment 28 of the papillary anchor 9. The locking segment 28 isa band of the papillary anchor 9 that can be flexed to open a gap forthe artificial chordae line 14 to pass through. In the natural shape ofthe papillary anchor 9, when no forced is applied, this locking segment28 fits closely with the remainder of the anchor 9 and so it will holdthe artificial chordae line 14 in place. The Z-shaped fork 20 is used tohold the locking segment 28 open until the artificial chordae line 14 isthe correct length. The cutting piece 18 cuts the artificial chordaeline 14, which is pulled against the blade when the adjustment processis completed.

FIGS. 16 to 19 include more details of the papillary anchor 9, includingits hooks 62 which are formed by curving pins 62. FIGS. 16 and 17 showone possible form for the hooks 62, with a central slit 64 and a seriesof holes 66 threaded with a suture 68. As discussed above, this suture68 and the holes 66 can allow the hooks 62 to better engage with bodytissue during healing, as well as keeping the material of the hooks 62connected to the main body of the papillary anchor 9 in the event of abreakage. FIG. 16 shows the folded/constrained shape of the hook 62,which is also the shape of a tine formed in a tubular section duringmanufacture of the anchor 9, prior to heat setting to form the curve.FIG. 17 shows the curved form of the hook 62, i.e. theunfolded/unconstrained form.

FIGS. 18 and 19 show an example of an entire papillary anchor 9, againillustrating the folded (FIG. 18) and unfolded (FIG. 19) configurations.This papillary anchor 9 includes hooks 62 with an opening in the form ofa slit 64, which gives various advantages as discussed above, includingbetter engagement with the body during healing as well as increasedsurface area without loss of flexibility.

The device can include a safety wire 72 that acts to prevent thepapillary anchor 9 from escaping into the body in the event that it isnot correctly placed. Once the locking and cutting have been done, andthe papillary anchor 9 is seen to be secured to the papillary muscle 26and to the leaflet anchor 10 then the safety wire 72 is cut.

In order to deploy the leaflet anchor then a U-rod can be used. ThisU-rod 30 would be housed within the gripper arm 30 and partly within themain part of the catheter, with a free end of the U-shape being used topush the leaflet anchor 10 (and ejector unit 36, where present) alongthe leaflet anchor tube 38. The U-rod has a bendable section so thegripper can open and close, while the U-rod is inside. Advantageously,this bendable section can act as a sort of a spring, applying arestoring force to return the gripper arm 30 to the closed position. TheU-rod is made of a material with the ability to deform elastically to ahigh degree in order to allow for the bending of the bendable section.Suitable materials include shape memory materials, for example shapememory metals such as nitinol. A shape memory metal also has theadvantage that the U-rod can be made stiff, which makes the transfer offorce with the U-rod more efficient. The U-rod may consist of a thinnitinol wire and tubes on the outside of the wire, to make the U sectionstiffer. Alternatively, the U-rod could be made of several types ofmaterials to achieve the required properties.

As noted above, imaging techniques such as 3-D ultrasound or fluoroscopycan be used when guiding the device and to confirm the correct locationof the leaflet 12 within the gripper device 6. To assist in this, theechogenic properties of the device may be improved by abrasive blasting,mechanical texture or a special coating, for example an echogenicpolymer coating. The gripper device 6 can also be provided with adetection system to confirm the location of the leaflet 12 within thegripper 6. In a modified gripper (not shown) a fluid based sensor systemis provided. This uses holes on the gripping surface of the gripperhousing 4. The holes are connected through tubes to a fluid supply, suchas contrast fluid from a syringe. When the gripper pinches the leaflet(or other tissue), the holes will be blocked by tissue preventing theflow of fluid. This can be used to determine if the leaflet is in thecorrect position to deploy the leaflet anchor. The device could be builtwith various numbers of holes, for example three or four, with thecombination of open and closed holes being used to determine theposition of the leaflet/tissue within the gripper 4. If four valves areplaced in a square pattern, two closed and two open valves couldrepresent the correct position of the leaflet. In one example, thesensor system consists of one-four fluid channels that can be located inthe instrument wall, opposite of the gripper arm, alternatively in thegripper arm tip. The channels are connected to ports on the instrumentshandle where they can be injected with a contrast fluid, which can bevisible on either echocardiography or fluoroscopy. An absence (orreduction) of visible fluid and/or the increased resistance to injectfluid in both channels tells the operator that the leaflet is correctlyplaced prior to leaflet anchor deployment.

In another example a pump with a monitoring circuit constantly pumps asmall amount of water through the tubes of the sensor. The detectioncircuit can detect pressure rise or change in the volume going througheach tube, the rise in pressure can indicate which tubes that areobstructed and to some degree says something about how thick the tissuein the leaflet actually is (thinner tissue tend to cause less pressurerise, relative to thicker tissue). The monitor device can for example beequipped with simple LEDs that go green if leaflet is properly gripped.This will give physicians further confirmation (in addition toUltrasound) that they have captured the leaflet correctly, whichultimately results in higher procedure success rates. In a slightlydifferent embodiment the pump can be programmed to slowly pump fluid inand out of the tubes, which does not require additional fluid if theprocedure takes long time.

The device may include a suture/line management system, to preventtangling. Sutures may be held inside slits or tubes, until everything isready for them to be released, this will reduce the chance ofentanglement. The suture slit in the papillary housing 8 may be equippedwith a one way “suture valve” cut from the nitinol tube itself, it willprevent native chordaes from entering the chordae channel.

The artificial chordae line 14 can be attached to the anchor(s) inseveral ways. For example, wire through holes with knots, welds or glue.The artificial chordae line 14 can be made of Gore-Tex® suture material,or a thin nitinol wire. This preferred embodiment uses Gore-Tex® sinceit is easier to cut once the length has been adjusted. The artificialchordae line 14 has a diameter of approximately 0.1-0.6 mm. The leafletanchor 10 is approximately 1-2 mm in diameter, and approximately 4-6 mmin length (when straight).

The leaflet anchor pins can be cut with several different profiles toachieve different strength, and/or faster healing. Since the leafletanchor 10 is cut from tubing using laser cutting then different shapesare easy to produce. The pins of the anchor may for example have astraight edge (minimum friction) or a profile for increased friction,such as a smooth or sharp saw tooth, or a barbed profile. The anchorshape can vary based on the requirements of the procedure. Differentanchor designs could be available for a surgeon to select based on theirassessment of the patient.

As with the leaflet anchor pins, the papillary anchor pins can be cutwith several different shapes to achieve different pull out strengthand/or faster healing. The pins of the anchor may for example have astraight edge (minimum friction) or a profile for increased friction,such as a smooth or sharp saw tooth, or a barbed profile. The anchorshape can vary based on the requirements of the procedure. Differentanchor designs could be available for a surgeon to select based on theirassessment of the patient.

FIGS. 20 to 22 illustrate interaction of the papillary anchor 9 with thechord and a cutting piece 18 of the catheter device. The cutting piece18, is made of a suitable biocompatible material, preferably cut withlaser and sharpened by grinding away some material. The material may forexample be stainless steel, titanium or titanium alloy. Nitinol couldalso be used. The Z-shaped fork 20 is used to hold the locking segment28 open to make room for the chord between the locking rings and lockingsegment 28 in the papillary anchor 9.

Once the papillary anchor 9 is placed and the delivery device isretracted, as discussed above, then a chordae-wire 14 is used to adjustthe chordae length. An optional wire lock (not shown) can be pulled togently pinch the artificial chordae line 14 in the temporary adjustedstate during analysing of the length, the wire-chordae will in additionbe held from the outside. Once the correct length is achieved, a lockingwire 70 is pulled, which bends/retracts the Nitinol Z shape 20 and locksthe chordae in place by releasing the locking segment 28. Then thecutting piece 18 is pulled and its nitinol knife engages with theartificial chordae line 14 as well as one strand of a papillary anchorholder suture 72. The papillary anchor 9 is now free from the adjustmentand cutting device 18, 20.

The use of the Z shaped nitinol fork 20 to hold the locking segment 28open allows the suture/chordae pathway to get a very gentle curve. Italso allows the suture to come out of the device in line with thegripper opening. This is important to get as good as possible loadconditions on the papillary anchor (Chorda comes out of the anchor inthe correct place for optimal holding strength).

In one embodiment the cutter 18 is made from a thin sheet nitinol, whichallows the blade to be pulled around a curved surface, to allow aminimal footprint of a relative long sliding action component (it can bepulled for example perpendicular to the cutting surface, taking up muchless space). The Z-fork 20 can be produced from a laser cut heat setNitinol sheet part, where certain sections can be grinded thinner, toobtain different thickness and flex along the part. It is possible toadd in a simple temporary wire lock, when pulled it will gently squeezethe chordae 14 in order to maintain its temporary adjusted length, inaddition to hold the wire that is connected to the chordae 14 on theoutside (not in illustrations). Note that the supports inside theadjustment device 21 are not shown. The chamfer on the top part ofadjustment “box” will allow the device to find the anchor 9 if it needsto be retrieved.

In one embodiment a push out tube connected to the papillary anchor 9contains several markers that can be used as a rough reference point onthe distance between the papillary anchor and the leaflet anchor, thiscould allow the physician to roughly adjust the chordae prior to do thefinal adjustments as they normally have a hunch about how long the finalchordae length should be.

To prevent the cutter 18 from exceeding its desired range of motion, thecutter 18 may be equipped with two stopping features disposed at anupper and lower end of the cutter 18. To prevent the cutter 18 frommoving further than its upper position in the housing, a cutter wire maybe threaded through the housing and/or the cutter to stop the cutter 18in an upper position. Even if the cutter wire were to break, the cutter18 and a wire attached to the cutter operating it cannot escape from anupwards end of the housing as both are contained within the housing. Toprevent the cutter 18 from moving further than its lower position in thehousing, a cam may be used.

The shaft of the part of the catheter device 2 which houses the cutter18 and the adjustment device 21 (not shown) can be constructed with twolumens: one chordae lumen and one cutter lumen. The construction can bereinforced with braiding around the chordae lumen (the shaft may alsoinclude any lumens required to house pullwires used for operating thedevice, which may also be reinforced with braiding). In addition to thebraiding, a wire made out of Kevlar or another similar material may beimplemented in the construction running along the length of the shaft,to increase the tensile strength of the device 2. Additionally oralternatively, a composite tube may be positioned around the lumens. Thecomponents and tubing of the shaft can also be embedded in a softpolymer, such as Pebax (e.g. by Pebax reflow), to allow for sufficientflex. The composite tubing may also be anchored in the distal end toprevent the tubing from being torn out of the soft polymer duringactuation of the cutter wire. The composite tubing may be anchored inthe distal end with, for example, a flat ribbon coil, a stainless steelhypotube ring, or a stainless steel collar.

The braid around the chordae lumen may comprise a laser cut hypotube,which increases the tensile and compression strength of the of the shaftconstruction. The laser cut hypotube can be ‘flex tailored’ such thatdifferent sections have different flex patterns to accommodate a desiredmovement of the shaft. The laser cut hypotube can also be weldeddirectly onto the head of the cutter 18. The strong bond between thecutter head and the laser cut hypotube allows for more reliableretrieval of the papillary anchor if readjustment is desired. A braidedcomposite tubing may be disposed outside the laser cut hypotube to formthe wire lumens.

In some cases the natural chordae could be a problem for the device.There is a risk of fouling if one of the existing chordae is caught inthe hole provided for the exit of the new artificial chordae line 14.One way to eliminate this is to have a one-way chord exit so that theartificial chordae line 14 can only go out of the device, and not in,although this feature is not essential.

Inside the papillary housing 8 there may be small notches in the wallsto hold the pins of the papillary anchor 9 and prevent the papillaryanchor 9 from rotating so that the pins could fold out in the openingfor the new chord 14.

As set out above, one form for the anchor is a grapple hook shape.Another possibility with particular advantages for the leaflet anchor 10is an anchor with an elongate shape, such as a slim straight body or anelongate tubular form. Examples of such anchors 10 are shown in FIGS. 23to 28. The elongate anchor 10 can be used in place of the grapple hookshaped anchor 10 discussed above, and thus for example can be used inthe catheter device and paired with a papillary anchor as shown in FIGS.1 to 22.

FIGS. 23 to 26 show one advantageous form of elongate anchor 10 in useas a leaflet anchor 10. The leaflet anchor 10 of FIGS. 23 to 26 has anunfolded configuration for placement within the body tissue, which isshown in FIGS. 25 and 26, and a folded configuration for use prior todeployment of the anchor 10, which is shown in FIGS. 23 and 24. Theunfolded configuration is a U-shape and is permits placement of theanchor 10 into an anchor tube 38 prior to deployment using a similarmechanism to the leaflet anchor deployment mechanism described above.Thus, the example implementation uses an ejector unit 36 that grasps theleaflet anchor 10 via a grasping device 50, and the ejector mechanism 36also includes a suture pusher (line pusher) 58. The anchor 10 isattached to an artificial chordae line 14, which can in turn be attachedto a papillary anchor as discussed above. The function and structure ofthe leaflet anchor deployment mechanism is generally as discussed above,aside from that the anchor has a different form as shown.

The elongate leaflet anchor 10 can be elastically deformed into thefolded configuration with a U-shape as shown in FIGS. 23 and 24, withFIG. 23 showing a cross-section including the leaflet anchor tube 38,and FIG. 24 showing the folded configuration with the leaflet anchortube 38 omitted from the drawing. The elongate leaflet anchor 10includes two pins 82, which form the arms of the U-shape in the foldedconfiguration. There are sharp tips 84 at the end of each of the pins82. The fold of the U-shape is centred on the anchor's centre 80, whichis where the artificial chordae line 14 is attached. The ejector unit 36grasps the elongate leaflet anchor 10 at either side of the centre 80via hooked arms 50 similar to those described above. The anchor elongateleaflet 10 is held in the U-shape by application of a constraining forcefrom the walls of the leaflet anchor tube 38, and it will return to theunfolded configuration when no constraining force is applied, whichoccurs when the elongate leaflet anchor 10 has been pushed out of theend of the leaflet anchor tube 38. FIG. 25 shows this configuration,with the ejector unit 36 also having been moved to its secondconfiguration in order to release the elongate leaflet anchor 10. Asnoted above, the ejector unit 36 can have a form and function asdescribed above, for example as described in connection with FIGS. 8 to12. In the unfolded configuration the elongate leaflet anchor 10straightens out into an elongate configuration in which the two anchorpins 82 extend in opposite directions to each other, preferably paralleland opposite to one another, with one pin 82 at either side of thecentre 80, where the line 14 is attached.

Thus, when the elongate leaflet anchor is in its folded U-shape and itis advanced out of the end of the leaflet anchor tube 38 via the leafletanchor deployment mechanism then the ends 84 of the anchor pins 82 willpierce the leaflet 12 and pass through it. As the centre 80 of theelongate leaflet anchor 10 approaches and then passes beyond the end ofthe anchor tube 38 then it will straighten out into the shape shown inFIG. 25. Hence, when the elongate leaflet anchor 10 assumes the unfoldedconfiguration the elongate form will be threaded through the leaflet 12with outer parts of the two pins 82 one side of the leaflet 12, and thecentre 80 of the elongate leaflet anchor 10 as well as central parts ofthe two pins 82 on the opposite side of the leaflet 12.

FIG. 26 shows a possible further advantageous feature, where theelongate leaflet anchor 10 is enclosed with an ePTFE sheath 86. Thepurpose of the ePFTE sheath 86 is to promote tissue growth into andaround the anchor during healing, as well as to protect the anchor 10and allow it to be retained in a single piece in the event of afracture. The sheath 86 is attached to the main body of the anchor 10 bysutures.

In the example of FIG. 23 to the anchor is formed from an elongate platewith a curve across its width. The curvature across the width is used toincrease the stiffness of the anchor and hence to increase the forcewith which the anchor pushes back toward the unfolded configuration.Once the anchor is folded the bottom curvature will become flat, whichmeans that further folding needs only a relatively small force. Theoriginal curvature impacts on the amount of elastic strain in the anchormaterial when it is flat, which in turn affects the elastic forces thaturge the anchor to return to the unfolded configuration. A typicalcurvature might be in the range 1-5 mm radius for a thickness of theplate in the range 0.05 to 0.5 mm. To obtain a curved plate the anchormay be formed from a flat plate that is deformed and heat set.Alternatively a curved plate could be provided as a section cut from atube of the required curvature. The latter approach can involve fewermanufacturing steps since pre-existing tubular sections can be used toprovide the required curvature.

In an alternative example, as shown in FIGS. 27 and 28, an elongateleaflet anchor 10 can be formed from a tubular body with a weakenedsection at its centre 80 to allow for elastic bending of the tube. Thiselongate leaflet anchor 10 can be folded into a U-shape and unfolds intoan elongate generally straight form as for the elongate leaflet anchor10 of FIGS. 23 to 26, and it will be appreciated that it may be deployedvia a leaflet anchor tube 38 and ejector unit 36 as discussed above. Toprovide sharp ends 84 of the pins 82 then diagonal cuts are made acrossthe tube, leaving sharp ends 84 similar to those on hollow needles. Theweakened section at the centre 80 of the tube can be provided by cuttingone or more openings into the tube, such as shown in FIGS. 27 and 28.

A possible further feature of the catheter device is shown in FIG. 29.This is a sliding chordae holder 88 that can be used in the pathway ofthe artificial chordae line 14 through the flexible and extendable joint34 and down to the papillary anchor 9 in the distal part 8 of thehousing. The sliding chordae holder 88 is fixed in place relative to theproximal end of the device and hence does not move relative to theproximal part 4 when the flexible and extendable joint 34 extends. Itthen slides relative to the distal part 8 of the housing. The slidingchordae holder 88 reduces the risk of pinching the artificial chordaeline 14 in the flexible and extendable joint 34. As best seen in thelower enlarged section the sliding chordae holder 88 includes a channel90 that holds the artificial chordae line 14. Further, as best seen inthe upper right view, where the housing is omitted, the sliding chordaeholder 88 has a profile formed with side rails for guiding the slidingmovement.

In addition the sliding chordae holder 88 can reduce the risk ofpinching the line 14 in any other flexible joints, such as a flexiblehinge section that moves with the gripper arm 30 in the proximal housingpart 4. A suture push out device can be provided to allow for the userto selectively push out the artificial chordae line 14 from channel 90of the sliding chordae holder 88. In that case a thin line may be placedbelow the artificial chordae line 14 in the channel 90, with the thinsuture being connected to a small sliding wedge such that when pulledthe wedge moves inside the channel 90 in order to push the artificialchordae line 14 of out the channel 90. This feature allows the user tochoose the point at which they release the artificial chordae line 14from the device, which further reduces the risk of entanglement.

It would also be possible to use the thin wire in order to split open aninitially closed channel by breaking along a weak point or by unfoldingthe tube about a slit. That could mean that the artificial chordae line14 is initially enclosed, but when the wire is pulled then a protectivecover is opened or otherwise removed from the outer surface of thechannel 90 and allows the artificial chordae line 14 to escape thechannel 90, or to be pushed out via the suture push out device.

FIG. 30 shows an alternative way to arrange the adjustment and cuttingcatheter 21 with features together with the papillary anchor 9. Thearrangement shown holds the line clamping mechanism in an open position,fixes the papillary anchor 9 to the adjustment catheter 21 and providesa way to cut excess line 14.

An internal cam 91 may hold the papillary anchor locking segment 28 inan open position, i.e. with the slit open, and the cam 91 advantageouslyperforms several tasks at the same time. The cam 91 can open the slit ofthe locking segment 28 as well as fixing the papillary anchor 9 to theadjustment catheter 21. In addition a cutting section 94 can be fittedto the cam wedge 95 that holds the cam 91 in the open position allowingthe excess artificial chordae line 14 to be cut in the same movement.This reduces the need for wires going through the adjustment catheter21. The cam 91 is held in place and supported by a holder that preventsthe cam from twisting and or bending when actuated. The adjustmenthousing 92 may have protruding features or an interference fit aroundits perimeter that snaps in place with support brackets inside thedistal part of the device, to allow the adjustment catheter 21 toextended the flexible and adjustable joint 34 then push out thepapillary anchor 9, once the right amount of counter-pressure is exertedby tissue on the distal part 8 of the catheter device.

In this example the papillary anchor 9 locking segment 28 is held openwith an internal cam 91. The cam 91 has a rest position (not shown inFIG. 30, but note that there is a similar arrangement in FIGS. 41 and 42below) and one open position, as shown in FIG. 30, with the cam 91 inits open position the papillary anchor 9, and locking segment 28 areheld open by internally applying a constraining force. The cam 91 isheld in place by a housing 92 that supports the cam 91 structurallyduring its travel. In addition the adjustment housing 92 contains a linechannel 93 and a sliding channel 99 for a combined cutting and cam wedgepiece 96/95. When the cam wedge 95 is engaged with the cam'swedge-grooves 98 the anchor locking ring 28 is held open, the artificialchordae line 14 may then be threaded through the line channel 93 andthrough the open locking rings 28 with relatively free passage. Once awire 97 connected through attachment hole 100 in the cutting wedge 96 ispulled, the wedge 95 disengages from the wedge-grooves 98 and the cam 91returns to its rest position, clamping the line 14 and releasing thepapillary anchor 9 from the adjustment housing 92. During the release ofthe cam 91, or immediately after, the cutting knife 94 engages with theline 14. The cam 91 and cutting wedge 96 may have a cylindrical shape,to accommodate tight tolerance machining. One or both of the cuttingedges may also be fitted with flat or circular blades. An additional twolegged fork structure (not shown) connected to the wedge 96 that holdslocking segment 28 open may also be included to make sure the lockingsegment 28 of the anchor is completely open while the suture 14 isadjusted.

The adjustment housing 92 may have protruding features or aninterference fit (not shown) around its perimeter that snaps in placewith features in the distal part 8 of the device, to allow theadjustment catheter 20 to extended the flexible and adjustable joint 34then push out the papillary anchor 9, once the right amount ofcounter-pressure is exerted by tissue 26 on the distal part 8 of thedevice. It will be understood that the arrangement of FIG. 30 can becombined with any of the prior embodiments for the catheter device inplace or other arrangements for holding the papillary anchor 9 and foroperating the locking ring 28.

The adjustment housing 92 may have a groove (not shown) for a lockingtab (not shown) that holds the papillary anchor 9 in place to prevent itejecting too early as previously described. The locking mechanism can bea tab connected to a torque wire that locks into the papillary anchor 9.A suitable locking mechanism might include a latch as described belowwith reference to the device of FIGS. 34 to 36.

A variation of the design of the two-part housing section of thecatheter device 2 is shown in FIG. 31 and FIG. 32. FIG. 31 is a sideview of the housing section with a flexible joint 34′ angled and thegripper device 6 open. FIG. 32 shows the two-part housing section in astraight configuration, with a chordae channel 90′ visible. This designfor the two-part housing section may be used in place of the flexibleand extendable version described above, with other features of thedevice remaining the same. It has been found that it is possible toreliably complete implantation of both of the anchors in a singleprocedure using such a device, where the flexible joint 34′ allows thedistal end to be angled toward the papillary muscle 26 for implantationof the papillary anchor 9 without the use of an extension of the distalend. This variation also illustrates the possible use of differentmaterials, since the two-part housing section(s) and the gripper may beformed from a composite such as fibre reinforced PEEK, which again maybe a variation applied to other arrangements for the catheter device 2as discussed above. This type of composite material can give greatervisibility of the device via ultrasound imaging during image guidedsurgery, with the visibility optionally further enhanced by addedreflection enhancing features such as the use of dimples 102 as shown.The two parts of the two-part housing section are joined by a hingeelement 104, which can be actuated via one or more wires (see FIG. 46).Pull wires that actuate the device may beneficially be threaded aroundthe hinge element, which provides a low friction transition in thepulling direction. Other features of the device can be similar to thosediscussed above, such as the gripper mechanism 6, and the anchordeployment systems.

FIG. 33 shows a cross-section view of another example of a catheterdevice 2. The gripper arm 30 may be seen engaged with the gripperhousing 4 in a closed position, ready to deploy the leaflet anchor 10.

The leaflet anchor channel, inside the gripper arm 30 may be producedwith one or more anti-rotation grooves 122 in the form of one or moreslits or grooves 122 running along the inside of the leaflet anchorchannel in the gripper arm 30. The grooves 122 assist in preventingrotation of the leaflet anchor 10 during its deployment when engagedwith a suitable engaging mechanism (not shown). In this example at leastone of the tips of the hooks of the leaflet anchor 10 slide inside thegroove(s) 122, preventing the leaflet anchor 10 from rotating. Anon-circular oval shape (not shown) may also be utilised to preventunwanted rotation of the leaflet anchor 10.

Running through the catheter device 2 of FIG. 33 and into a distal endof the catheter device 2 is an adjustment catheter 21. As describedabove, the adjustment catheter 21 is able to control the extension ofthe flexible joint 34 by means of wires and/or rods 60. The same wiresand/or rods 60 also push out the papillary anchor 9 for deployment. Asdescribed above, the papillary anchor 9 comprises a number of pins 62that in an unconstrained configuration form a number of hooks, andfurther comprises a locking segment 28 disposed within a wall of thepapillary anchor 9. The papillary anchor 9 is housed within thepapillary anchor housing 8. Further housed within the papillary anchorhousing 8 is an adjustment housing 92. The adjustment housing comprisesa piston 110, an anchor holder 106 and a cam 91. To prevent unwanteddeployment of the papillary anchor 9, a deployment lock mechanism 111using a latch 113 may be disposed within the papillary anchor housing 8,as shown in FIG. 34. The deployment lock mechanism 111 is actuated via alocking spring that acts on the latch 113 and a deployment lock wire112. The latch 113, the locking spring, and the deployment lock wire 112may be formed from a suitable elastically deformable alloy such asnitinol. The latch 113 is engaged with a recessed slot 115 of thepapillary anchor housing 8 in order to lock the adjustment housing 92 inplace relative to the housing 8. The deployment lock wire 112 may besituated within the adjustment catheter 21 for operating the latch 113.The deployment lock wire 112 extends from the latch 113 to the proximalend of the catheter device 2. The deployment lock wire 112 may also beenclosed in a flexible tube (not shown) which may assist in facilitatingreengagement of the deployment lock wire with the latch 113, ifnecessary.

FIG. 35 shows the deployment lock mechanism 111 in a locked positionwithout the papillary anchor housing 8. A retainer pin 116 permanentlyconstrains one end of the latch 113 to be engaged with the papillaryanchor housing 8, and acts as a pivot for the latch 113. The deploymentlock wire 112 temporarily constrains the other end of the latch 113 tobe engaged with a chamfered cavity 114 of the anchor holder 106, theanchor holder 106 capping the end of the papillary anchor 9 opposite toits hooks.

As shown in FIG. 36, the deployment lock wire 112 may be retracted. Onceretracted the deployment lock wire 112 no longer constrains the latch113 to engage with the chamfered cavity 114 of the anchor holder 106.The locking spring can then move the latch 113 as set out below.

Shown in a magnified illustration within FIG. 36, without constraintfrom the deployment lock wire 112 the latch 113 only rests within thechamfered cavity 114 of the anchor holder 106. When a forward pressurefrom the wires and/or rods 60 within the adjustment catheter 21 areoperated, a forward pressure is applied to the anchor holder 106 andpapillary anchor 9, which in turn releases the anchor holder 106 fromthe latch 113. This is achieved due to the shape of the chamfered cavity114 deflecting the latch 113 during the deployment motion.Advantageously, if an operator of the catheter device 2 wishes toreengage the deployment lock mechanism 111 with the anchor holder 106; achamfer on the proximal end of the anchor holder 106 may deflect thelatch 113 in order to reengage with the chamfered cavity 114 in its restposition. The deployment lock wire 112 may then be reengaged with thelatch 113. As such, the deployment lock mechanism 111 may suitably beengaged and disengaged as required to allow or prevent deployment of thepapillary anchor 9.

It will be appreciated that the lock deployment wire 112 may be used toconstrain the latch 113 against the chamfered cavity 114, whereby thelatch 113 instead has an undeformed position whereby it does not restwithin the chamfered cavity 114. However, if the latch 113 is in an openconfiguration at rest the capability of the deployment lock mechanism111 to be reengaged may be lost.

FIG. 37 illustrates a cross-sectional view of the papillary anchor 9when undeployed with the adjustment housing 92 mounted on top. Containedwithin the adjustment housing 92 is an anchor holder 106, a piston 110and a cam 91. The piston 110 comprises a fork-wedge formation 95, whichis configured to elastically deform the cam 91 and the papillary anchor9, and a cutting wedge 96, which is configured to cut the chordae 14 incombination with a cutting section 94 of the anchor holder 106. Thefork-wedge can be considered with two main parts, a cam wedge where atleast one tine of the fork-wedge 95 is used to open the cam 91, and apiston wedge where at least one tine of the fork-wedge 95 is used toopen the locking segment 28. The pointed end of the piston wedgeadvantageously assists in deflecting the locking segment 28 when thepiston wedge and the locking segment are engaged, makingengagement/deployment of the anchor 9 with the piston wedge easier. Whenthe cam 91 is engaged by the fork-wedge 95, the cam 91 elasticallydeforms the locking mechanism 28 of the papillary anchor 9 to an openposition. In the configuration shown in FIG. 37, the open lockingmechanism 28 and the positioning of the piston 110 within the adjustmenthousing 92 allows the chordae 14 to slide through with minimal friction.The chordae 14 is attached to the leaflet anchor 10 (not shown) abovethe papillary anchor 9. In this configuration the chordae is thus easilyadjustable in length. The piston 110 ideally features a piston wirelocation 97 which allows a pull-wire (not shown) to be attached to thepiston 110. The pull-wire is ideally disposed through the adjustmentcatheter 21 (inside a separate lumen in the adjustment catheter 21)without running through the path proximal to the cutting wedge 96 andcutting section 94. When the piston pull-wire is pulled, the piston 110slides in a direction away from the papillary anchor 9.

FIG. 38 illustrates a cross-sectional view of the papillary anchor 9when deployed with the adjustment housing 92 mounted on top. The piston110 slidably moves away from the papillary anchor 9 during deployment.In doing so the fork-wedge 95 of the piston is no longer engaged withthe cam 91 and the locking segment 28. The cam 91 no longer elasticallydeforms and the cam 91 as well as the locking segment 28 of thepapillary anchor 9 returns to their at rest/undeformed positions. Indoing so, the chordae 14 is locked in position and its length is nolonger adjustable. Concurrently, when the locking mechanism 28 returnsto its undeformed position the cutting section 94 and the cutting wedge96 cut the chordae 14. Thus in one motion the papillary anchor 9 may bedeployed and the chordae 14 suitably attached in place. By disposing thepiston pull-wire in the piston pull-wire location 97 above the cuttinglocation, the piston pull-wire may avoid being cut in the same actionand thus leaves the device fully operational should readjustment berequired.

To prevent the piston 110 from exceeding its desired range of motion,the piston 110 may be equipped with two stopping features disposed at anupper and lower end of the piston 110. To prevent the piston 110 frommoving further than its upper position in the housing 92, a cutter wire(not shown) may be threaded through the housing and/or the piston tostop the piston 110 in an upper position. Even if the cutter wire wereto break, the piston 110 and a wire attached to the piston 110 operatingit cannot escape from an upwards end of the housing 92 as both arecontained within the housing 92. To prevent the piston 110 from movingfurther than its lower position in the housing 92 is the cam 91.

FIGS. 39 to 42 show the adjustment housing 92 and the papillary anchor 9interactions in more detail.

FIG. 39 illustrates the adjustment housing 92 mounted on top of thepapillary anchor 9 when the papillary anchor 9 hooks are notconstrained. The adjustment housing 92 may be formed of a material suchas stainless steel or a composite material, such as CRF PEEK or acombination where the cutting edges may be Stainless steel while thestructural components may be a composite material. The fork-wedge 95,which in this embodiment comprises three legs but could comprise one ormore legs or tines, of the piston 110 is engaged with the lockingmechanism 28 of the papillary anchor 9. The fork-wedge 95 prevents thelocking mechanism 28 from returning to its undeformed position and thusallows for adjustment of the chordae line 14 passing through it. Thecutting wedge 96 is disposed on one of the tines corresponding to thefork-wedge 95.

FIG. 40 shows the adjustment housing 92 without the papillary anchor 9.The adjustment housing 92 comprises the anchor holder 106, the piston110 and the cam 91. The adjustment housing 92 is in an adjustmentconfiguration, shown by the piston 110 engaging with the cam 91 via thefork-wedge 95 to elastically deform the cam 91 to a wide position. FIG.40 also shows an engaging portion 108 of the anchor holder 106. Theengaging portion 108 is shaped such that it fits within the papillaryanchor housing in a specific orientation whereby rotation is restricted.

FIG. 41 is a birds-eye view of the cam 91 engaged with the papillaryanchor 9 in the deformed position. The deformation is the result of thepiston 110 engaging with the cam 91 via the cam wedge part of thefork-wedge 95. The deformation of the cam 91 constrains the lockingmechanism 28 of the papillary anchor to display an ovoid shape. Theovoid shape of the locking mechanism 28 not only allows for the passageof the chordae 14 through the locking mechanism 28 with minimalfriction, but also creates a shape of the papillary anchor 9 that may beutilised to restrict rotation of the papillary anchor 9 when disposedwithin the papillary anchor housing 8.

FIG. 42 is a birds-eye view of the cam 91 in its undeformed position.The piston 110 is not engaged with the cam 91 in this configuration. Assuch the cam 91 does not engage with the locking mechanism 28 of thepapillary anchor 9. The locking mechanism 28 when undeformed matches thetubular shape of the papillary anchor 9.

FIG. 43 shows two perspective views of the papillary anchor 9 with theadjustment housing 92 mounted on top, and three perspective views of thepapillary housing 8. The engaging portion 108 of the anchor holder 106features an ovoid cross-section with bevelled edges. During insertion ofthe papillary anchor 9 into the papillary anchor housing 8, the curvedinternal shape of the papillary anchor housing 8 deflects the engagingportion 108 due to the complementary curved shapes. The papillary anchor9 thus orients itself such that the ovoid shape of the locking segment28 will then engage with the complementary internal shape of thepapillary anchor housing 8.

The internal shape of the papillary anchor housing 8 may be seen clearlyin the middle perspective view of FIG. 43, looking from the distal endof the papillary anchor housing 8. Towards the proximal end, a shapecomplementary to the engaging portion of the anchor housing 106 isgraduated from the ovoid shape complementary to the locking mechanism28. The funnelling shape assists in deflecting the engaging portion 108of the anchor housing 106 such that the correct orientation is easilyachieved to insert the papillary anchor 9 within the papillary anchorhousing 8. The funnelling allows for the correction of relatively largerotational misalignment before the anchor holder 106 engages with thecorresponding slot within the papillary anchor housing 8 which greatlyrestricts rotational movement.

The specific shapes of the locking mechanism 28, the engaging portion108 of the anchor holder 106 and the internal shape of the papillaryanchor housing 8 restrict rotation of the papillary anchor 9.Restricting possible rotation of the papillary anchor 9 advantageouslyensures proper alignment of the papillary anchor 9 with the targetdeployment location. Additionally, the engaging portion 108 of theanchor holder 106 may feature chamfering to assist in more easilyinserting the anchor holder 106 into the distal part 8 of the catheterdevice 2.

Restricting rotation of the papillary anchor 9 may also assist inpreventing twisting of the chordae 14, the lock deployment wire 112, thepiston pull-wire and the wires/rods 60 used to deploy the papillaryanchor 9.

A number of the wires such as the lock deployment wire 112, the pistonpull-wire and the wires/rods 60 used to deploy the papillary anchor 9are disposed in the distal part 8 of the catheter device 2 to ensureproper functionality of the device 2. However, as the distal part 8 ofthe catheter device 2 is able to actuate to bend and/or extend, slackmay be introduced to some or all of the wires/rods used within thedevice 2 to operate its various components. This can lead toentanglement of the wires which may affect proper functionality of thedevice 2. To ensure that the wires/rods remain taut, a constant tensiondevice may be used within the device 2. The constant tension device maybe disposed in the handle used to operate the device 2. An example of aconstant tension device includes but is not limited to a constant forcespring.

A constant tension device as described above could also be implementedfor use with the U-rod wire 30 which, being disposed in the proximalpart 4 of the catheter device 2, is still susceptible to entanglementdue to bend or steering of the shaft of the device 2. Similarly, aconstant tension device as described above could be implemented for usewith the artificial chord 14 when it is disposed in the device 2 beforeadjustment and deployment.

FIG. 44 shows another view of the papillary anchor 9, when the piston110 is engaged with the cam 91. The locking mechanism 28 is elasticallydeformed and protrudes from the wall of the papillary anchor 9. Theovoid shape of the protrusion is utilised to restrict rotation of thepapillary anchor 9 within the papillary anchor housing 8. The bevelledshape of the engaging portion 108 may also be seen, which assists withdeflection of the anchor holder 106 to ensure correct orientation wheninserting the papillary anchor 9 within the papillary anchor housing 8.Also visible is a keyed joint arrangement 120 for guided alignment ofthe papillary anchor 9 as it engages with the anchor holder 106 of theadjustment housing 92. The circular tubular form of the examplepapillary anchor 9 fits with a concentric arrangement to an outercylinder of the distal part of the anchor holder 106. A cut-out in thepapillary anchor 9 can interlock with a protrusion on the anchor holder106 to provide the keyed joint 120. It will be understood that theopposite arrangement of the cut-out and protrusion could also be used.

FIG. 45 shows more detail of possible advantageous features for thedistal part 8 of the housing. In this instance the housing includes anon-circular mating groove 118 in the papillary anchor housing 8, whichmay be formed to allow for engagement with an ovoid shape of the lockingsegment 28 as discussed above. To allow for guided engagement of thepapillary anchor 9 and the anchor housing 108 a funnelled section 117 isprovided to facilitate rough alignment of the papillary anchor 9. Oncethe engagement is completed then the a key groove 118 prevents anyrotation of the non-circular shaped papillary anchor 9 and/or the anchorholder 106 while it is slid further along the papillary anchor housing8, i.e. the distal part 8 of the housing. Another feature that is bestseen on FIG. 45 is the presence of a chordae channel 124 running alongthe length of the papillary anchor housing 8. This channel 124 allowsspace for placement of the chordae line 14. As it is formed via a slitalong the length of the papillary anchor housing 8 then it also acts toreduce the rigidity of the papillary anchor housing 8, allowing for someelastic deformation as the anchor 9 is engaged/reengaged.Advantageously, the chordae channel 124 is placed in a thicker section126 of the wall of the papillary anchor housing 8, with this thickersection 126 being formed due to the non-circular shape of the recesswithin the housing 8 as well as the fact that this non-circular shape isplaced eccentrically, i.e. off-centre with reference to the centre ofthe outer form of the papillary anchor housing 8.

FIG. 46 shows how a hinge pullwire 204 for actuating the hinge element104 of the flexible joint 34′ of the catheter device 2 may be arranged.Although a single hinge pullwire 204 is shown in the figure, more thanone hinge pullwire 204 may be utilised to achieve the desired operationof the hinge element 104 of the flexible joint 34′. The hinge pullwire204 passes through a shaft of the catheter device 2, through theproximal part 4 of the two-part housing section and to the hinge element104, configured to angle a centreline of the distal part 8 of thecatheter device relative to a centreline of the proximal part 4. Asdescribed above, the hinge pullwire 204 that actuates the device may bebeneficially threaded around the hinge element 104, which provides a lowfriction transition in the pulling direction.

As can be seen in FIG. 46, the hinge pullwire 204 is off-centre relativeto the catheter device 2 and is instead disposed proximate a wall of thecatheter device 2. Thus the hinge pullwire 204 is routed to sit inside afront side of the device 2, i.e. the side of the catheter device 2 wherethe mechanical gripper device 6 is disposed. To angle the distal part 8of the catheter device 2, the hinge pullwire 204 is pulled. By locatingthe hinge pullwire 204 inside the front side of the device 2, the shaftof the catheter device 2 is also deflected in the direction the distalpart 8 is angled to relative to the proximal part 8. The actuation ofthe hinge element 104 and the deflection of the device 2 may besequential or simultaneous during operation of the hinge pullwire 204.For example, during operation of the hinge pullwire the device shaft maydeflect at the same time the hinge element bends, or during theoperation of the pullwire the hinge element may bend first and thedevice shaft may deflect second. Beneficially, the shaft of the device 2may thus be steered by the hinge pullwire 204 as the distal part 8 ofthe device 2 is angled. Additionally, this assists in ensuring that thedistal part 8 is positioned perpendicularly to the target wall of theheart during anchor deployment.

FIGS. 47A and 47B show exemplary knots that may be utilised to attach anartificial chord 14 to the leaflet anchor 10. The leaflet anchor 10could be in accordance with any of the embodiments of the leaflet anchor10 discussed herein. The knots shown in particular are self-locking,i.e. when tension is applied from the end of the artificial chord 14 notattached to the leaflet anchor 10, a stable knot forms. The exemplaryself-locking knots shown in the Figures can increase the tensilestrength of the leaflet anchor 10 connection by up to a factor of 2.5times compared to the tensile strength of anchors 10 implementingconventional knots.

Anchor holes 65 located in the base of the anchor 10 accommodate theknot. The holes 65 allow for many threading patterns that give asignificant amount of friction to the artificial chord 14. The frictiongiven from the leaflet anchor 10 reduces the change of the artificialchord 14 from slipping out of the anchor holes 65. Over time, ingrowthof tissue in the anchor base and therefore the knot improves thestrength of the knot over time.

As shown in FIGS. 48A and 48B, the piston wedge of the piston 110 may bearranged such that the piston wedge is never in contact with an internalwall 9′ of the papillary anchor 9. When the locking segment 28 isrequired to be in an open position (e.g. for adjustment of theartificial chord length 14), the piston wedge engages the lockingsegment 28 without engaging the papillary anchor wall 9′.Advantageously, as there is a smaller contact surface area between thepiston wedge and the papillary anchor wall 9′ than if the piston wedgewere in contact with the wall 9′, there is less friction between thepiston 110 and the papillary anchor 9. Thus, during deployment of thepapillary anchor from the anchor holder 110, the piston wedge does notmove with the anchor 9, hence ensuring that the piston wedge disengageswith the locking segment 28 in the desired manner.

Still in reference to the embodiment shown in FIGS. 48A and 48B, thelocking segment 28 exerts a contact force on the piston wedge, due toits elasticity, which could encourage the piston 110 to move such thatthe piston wedge contacts the papillary anchor wall 9′. To overcome thisundesirable force the piston 110 is arranged in the anchor holder 106such that the piston 110 acts as a cantilever, preventing the pistonwedge from being pulled towards the papillary anchor wall 9′. To ensurethat the piston wedge is not bent towards the locking segment 28 by thereaction force of cantilever action provided by the piston 110 inresponse to the force exerted by the locking segment 28, the piston 110and the piston wedge may be made of a suitably rigid material. As wouldbe readily understood, the piston 110 of the embodiment as shown inFIGS. 48A and 48B is compatible with any other of the embodimentsconcerning the piston 110 and its features discussed herein.

As described herein, wires, rods and/or sutures may need to be pulled tobe operated and/or adjusted within the catheter device 2. Some of theoperations that these components are designed to perform may require alimited force. To aid an operator of the device 2 in knowing when such aforce is applied to these components, a clutch can be utilised thatreleases when a certain torque is released. In various embodiments, itis valuable to allow the operator to know when the clutch is engaging.When the clutch is therefore a ratchet clutch, the operator may benotified that the clutch is engaged due to the clutch producing audibleclicks. The type of clutch capable of being implemented in the presentinvention is not limited to a ratchet clutch and can in fact be anyknown clutch compatible with the embodiments described herein. Forexample, an O-ring squeeze clutch may be implemented. In this example,the clutch releases when a certain torque is reached to prevent furtherforce being applied to the wires, rods and/or sutures with which it isengaged.

As shown in FIGS. 49A and 49B, an anchor 9 is in a folded configuration.Whilst FIG. 49A shows the anchor 9 having tips 160 which are not curvedtowards a central axis of the anchor 9, FIG. 49B shows an anchor 9having tips 160′ which are curved towards a central axis of the anchor9. FIGS. 50A and 50B show how the hooks 62 of the anchor 9 are shaped inthe unfolded configuration. FIG. 50A shows the unfolded configurationfor tips 160 as in FIG. 49A, whilst FIG. 50B shows the unfoldedconfiguration for tips 160′ curved as in FIG. 49B.

Focusing on the anchor 9 shown in FIG. 49B, the anchor 9 comprises anumber of hooks 62 which extend from a base 109 of the anchor to adistal end of the anchor. The ends of each hook 62 comprise a tip 160′.The hooks may also have openings 64 running along their length. The tips160′ are curved towards a central axis of the anchor 9, such that whenthe anchor 9 is constrained by a constraining force in its foldedconfiguration by a container device (for example, the distal part 4 ofthe catheter device 2 as discussed above) the tips 64 of FIG. 49B do notcontact the inner wall of the container device at their pointed ends.Instead, the contact point between the container tube and the anchor 9is a tangential contact between the tips 160′ and/or hooks 62, such thata smoother portion makes contact between the anchor 9 and the containerdevice. As a smoother contact is made, less force is needed to eject theanchor 9 from its housing during implantation in a target body tissue.Additionally, inward curvature of the tips 160′ prevents scraping and/orscratching between the tips 160′ and an inner surface of the containerdevice. This in turn prevents the production of shavings of the materialthe container device is made from, which may be deposited in the regionaround the target body tissue and may otherwise lead to haemorrhagingand/or an embolism that could result in stroke. The production ofshavings is most prevalent when the container device is made of a softermaterial than the anchor 9. For example, this issue arises when thecontainer device is made of CRF PEEK and the anchor 9 is made fromeither nitinol or stainless steel.

As may also be seen in FIG. 49B, the curvature of the tips 160′ curvingback towards a central axis of the anchor 9 may assist in ensuring thatthe tips 160 are perpendicular to a surface of a target body tissue thatthe anchor is to be implanted in. This minimises an axial force neededto implant the anchor 9, as the force pushing the anchor 9 into the bodytissue is more efficiently transferred to the tips 160′ of the anchor 9.The force pushing the anchor 9 may be applied by the anchor containertube, the anchor container tube comprising a number of wires and/or rods60 as described above. The anchor 9 may be deployed via a mechanism asdescribed herein with reference to the other Figures, such as amechanism including anchor holder 106 and/or a piston 110 as discussedabove.

Whilst the curvature of the tips 160′ seen in FIG. 49B are shown asbeing perpendicular, it will be appreciated that the tips 160′ of theanchor 9 may be angled relative to a surface of a target body tissuethat the anchor is to be implanted in, i.e. curving towards the centralaxis of the anchor 9. Thus, the curvature of the tips 160′ may be in therange of 0 to 30 degrees to the normal of the surface of the target bodytissue that the anchor 9 is to be implanted in. In various embodimentsthe range of values the curvature of the tips 160′ could take may be 0to 5 degrees, 0 to 10 degrees, 0 to 15 degrees, 0 to 20 degrees, 0 to 25degrees or 5 to 15 degrees.

The curvature of the hooks 62 and the tips 160′ of the anchor 9 assistsin pulling the anchor 9 through the target body tissue duringimplantation. This effect is realised due to a ‘springback’ forceexhibited as the anchor 9 unfolds from its folded configuration to itsunfolded configuration. As the tips 160′ display curvature towards thecentral axis of the anchor 9, the hooks 62 are pulled through the tissueduring unfolding of the anchor 9. As a result the force required duringimplantation of the anchor 9 in a target body tissue is reduced. It willbe appreciated that a consideration of the advantages achieved by thetips 160′ of the anchor 9 being angled versus perpendicular to a surfaceof the body tissue for implantation is to be considered such that theforce required to implant the anchor may be effectively reduced.

Anchors 9 having hooks 62 which do not curve back towards a central axiswhen in a folded configuration (as shown in FIG. 49A) tend toimmediately bend back into their unfolded configuration (as shown inFIG. 50A) without penetrating any particular distance into the targetbody tissue, unless a large amount of axial force is applied to theanchor 9 during implantation. However, anchors 9 having hooks where thetips are formed to curve towards a central axis (as shown in FIGS. 49Band 50B) will tend to penetrate a larger distance into the target bodytissue before the tips 160′ of their hooks 62 begin to curve outwardfrom the central axis as they move into their unfolded configuration (asshown in FIG. 50B), because the inward curvature of the tips 160′ causesthe first penetration of the tissue to be inward and/or parallel withthe axis of the anchor 9. Thus, a reduced axial force is required to beapplied to the anchor 9 from the container device to cause the initialpenetration of the anchor 9, and in some cases this may be no force withthe unfolding of the anchor 9 acting to draw it into the tissue so longas a distal end of the container device is in contact with a surface ofthe target body tissue. The springback force of the anchor 9 resultingfrom the inward curvature of the tips 160′ facilitates a trajectory ofthe hooks 62 of the anchor 9 that cause the anchor 9 to move along adeeper curve into the tissue, thereby causing the pulling effect asdescribed.

The curvature of the tips 160′ that prevents contact between the pointedends of the tips 160′ and an inner surface of the container tube may bebest described as follows. In the folded configuration of FIG. 49B thehooks 62 have a first curve portion extending towards a central axis ofthe anchor 9. The hooks 62 and the tips 160 then have a second curveportion that extends away from a central axis of the anchor 9. Finally,there is a third curve portion where the tips 160′ curve back towards acentral axis of the anchor 9 such that the pointed ends of the tips 160′are angled away from the inner surface of the container tube applyingthe constraining force. As such the curvature of the hooks 62 display atleast one point of inflection. In other words, the curvature of the tips160 and/or hooks 62 may be described as at least one of a reversecurvature, an opposite curvature or a sigmoid curvature.

When in the unfolded configuration, as shown in FIG. 50B, the hooks 64extend away from the central axis of the anchor 9 in a grappling hooktype shape. In the unfolded configuration the hooks have a curvaturewith at least one point of inflection, and the direction of curvature ofthe hook reverses at the tip 160′, with a different shape to thealternative curvature used for the anchor 9 of FIG. 50A, as can be seenby comparison of the encircled part of FIGS. 50A and 50B.

As may also be seen in FIGS. 50A and 50B, the hooks 62 of the anchor 9shown in the unfolded configuration of FIG. 50B cover a larger planarextent than the hooks 62 of the anchor 9 shown in the unfoldedconfiguration of FIG. 50A. By requiring that the tips 160′ are curved asdescribed above when unfolded, the surface area covered by the unfoldedanchor 9 is increased. This spreads the force applied by the anchor 9across the body tissue it is to be implanted in across a larger area andthus reduces the strain on the tissue during implantation of the anchor.

As shown in FIGS. 49A, 49B, 50A and 50B, the tips 160, 160′ may beshaped such that the widest part of the tip 160, 160′ is wider than apreceding portion of the hooks 62. When tissue regrowth occurs aroundthe anchor 9 once it has been implanted, the tissue may regrow aroundthe hook 62 which extends through the body tissue. As the widest part ofthe tips 160, 160′ is wider than the preceding portion of the hook 62,more force is required to remove the implanted anchor 9. Thisbeneficially reinforces the implantation of the anchor 9.

The shape of the tips 160, 160′ may be described as that of a teardrop,a leaf or a petal. That is, the tips 160, 160′ comprise a generallyovate shaped body which has a pointed end for engaging the body tissueduring implantation of the anchor 9. The ovate body is preferablyadjacent to the hooks 62, with the pointed end at a distal end of theanchor 9.

Whilst the shape of the tips 160, 160′ is shown in FIGS. 49A, 49B, 50Aand 50B as described above, the tips 160, 160′ may instead comprise ataper extending from the hooks 62 to the end of the tips 160, 160′.

Although not shown in FIGS. 49A, 49B, 50A and 50B, the anchor 9 maycomprise any of the other features suitable for the anchor 9 discussedherein. For example, the openings 64 need not be limited to the openings64 shown in the Figures. Moreover, the base 109 of the anchor 9 maycomprise a locking segment 28 as discussed herein.

FIG. 51 displays a device handle 200 for operating and controlling thecatheter device 2 as well as a steerable introducer (not shown) for thecatheter device. The device handle 200 comprises a rack 202, on whichone or more rack wagons 206, 206′, 206″ may be mounted. The rack wagons206, 206′, 206″ provide a number of supports to which one or moreoperating handles 220, 221, 222 may be mounted. The operating handles220, 221, 222 in turn are used to actuate one or more pullwires housedwithin a pullwire sheath 224 of the catheter device 2, to control thefunctionality of the catheter device 2 as described above. The pullwiresheath 224 may be a catheter, such as a 24 French catheter or any othersize suitable for use with the catheter device. The pullwires disposedwithin the pullwire sheath 224 may be disposed through the walls of thepullwire sheath 224, or along its centre, as required for the desiredfunctionality of the pullwires. The pullwire sheath 224 may be steerableand thus may be a steerable catheter.

The rack 202 shown in FIG. 51 comprises a base structure to which atleast two supports are mounted. A first support 203 a is located at adistal end of the rack 202, whilst a second support 203 b is located ata proximal end of the rack 202. The supports 203 a, 203 b provide amounting surface for a rail 203 c. Whilst the second support 203 b isseen to be at a greater raised height from the surface of the rack 202than the first support 203 a, it will be readily understood that varioussupport shapes and structures may be utilised to provide the mountingsurface for the rail 203 c. The rail 203 c provides a support structureto which the rack wagons 206, 206′, 206″ may be slidably mounted to. Itwill be readily appreciated that a number of suitable arrangements ofthe rack 202 may be implemented in the device handle 200 of the catheterdevice 2. For example, the rack 202 may comprise more than two supports203 a, 203 b, and the rail 203 c may take on a number of configurationsas long as the rack wagons 206, 206′, 206″ may be slidably mounted onthe rail 203 c.

Whilst three rack wagons 206, 206′, 206″ are shown in FIG. 51, anynumber of rack wagons 206, 206′, 206″ may be utilised in the devicehandle 200 as appropriate. Focussing now on a single rack wagon 206, therack wagon 206 is formed from a single piece of sheet metal. The rackwagon 206 comprises a bent shape, with a first portion of the rack wagon206 being perpendicular to a second portion of the rack wagon 206. Thefirst rack portion may lie in a plane parallel to that of the rail 203c, and comprise a number of legs which allow the rack wagon 206 to beslidably mounted onto the rail 203 c. A thumb screw 207 may then be usedto clamp the rack wagon 206 to the rail 203 c, to prevent the rack wagon206 from moving from its desired position. Thus during assembly (andvice versa for disassembly) of the delivery handle 200 shown in FIG. 51,the rack wagons 206, 206′, 206″ may be slid on to the rail 203 c fromthe proximal end of the rack 202. Thumb screws 207, 207′, 207″ are thentightened to clamp the rack wagons 206, 206′, 206″ at their respectivelocations. Advantageously, this allows the rack wagons 206, 206′, 206″to be mounted and/or removed from the rack 202 without using anyspecialised tools. The components of the device handle 200 may then betaken for sterilisation following any operation or procedure withrelative ease.

Still with reference to a single rack wagon 206, a second portion of thesingle piece of sheet metal may be perpendicular to the first portion.The second portion may comprise, at its end furthest from the bend inthe rack wagon 206, a slot of semi-circular, ovoid or any other suitablecross section to which a number of clamping devices may be attached. Thesecond portion of the rack wagon 206 may also comprise a flange disposedadjacent the slot, the flange configured to receive a thumb screw 217.The clamping devices may comprise a number of washers, O-rings and/orclamps which themselves provide support for the pullwire sheath 224 andthe operating handles 220, 221, 222. In addition to or as an alternativeto the washers, O-rings and/or clamps, a number of discs 216, 216′, 216″comprising round grooves may be disposed around the pullwire sheath 224and positioned on the slot of the respective rack wagon 206, 206′, 206″.A thumb screw 217, 217′, 217″ may be passed through the flange of eachrack wagon 206, 206′, 206″ to constrain the rotation of each disc 217,217′, 217″ and thus constrain rotation of the pullwire sheath 224 ifneeded.

Turning now to the operating handles 220, 221 and 222 shown in FIG. 51,a number of spacers and washers, O-rings and/or clamps keep theoperating handles 220, 221, 222 in their desired positions rigidly alongthe pullwire sheath 224. The spacers and washers, O-rings and/or clampsmay themselves also be disposed about the pullwire sheath 224. Whilstthree delivery handles 220, 221, 222 are shown mounted to the deliveryhandle 200, it will be readily appreciated that any number of deliveryhandles 220, 221, 222 may be mounted in the delivery handle 200 toachieve the desired operation of the catheter device 2 and theassociated introducer.

Focusing on the operating handle 220 shown mounted between the firstrack wagon 206 and the second rack wagon 206′, the operating handle 220may comprise a number of gears and/or dials 226 a, 226 b, 226 c. Eachgear and/or dial 226 a, 226 b, 226 c may control the actuation of apullwire disposed in the pullwire sheath 224. The operating handle 220is used to control the steering action of the steerable introducer, forexample with the pullwire actuated by any one of the gears and/or dials226 a, 226 b, 226 c being a part of a steering control mechanism or atwisting control mechanism for the steerable introducer.

The arrangement of the operating handles 220, 221, 222 can be changed tosuit the user preference and to align with a desired procedure. Forexample, instead of control of wires for the steerable introducer, thepullwire actuated by any one of the gears and/or dials 226 a, 226 b, 226c could be, but not limited to, the pullwire 204 operating the hingeelement 104 of the catheter device 2, and so on. Similarly, the gears,dials and other control inputs for the operating handles 221 and 222 maycontrol various elements of the catheter device 2. In one arrangement,the proximal operating handle 220 controls the steerable introducer aswell as advancement of the catheter device 2, the middle operatinghandle 221 controls various functions of the catheter device 2 relatingto grasping the leaflet and implantation of the leaflet anchor, and theproximal operating handle 222 controls further operations linked toimplantation of the artificial chord 14, such as adjustment and/orcutting of the chord 14. In addition, the relative location of theoperating handles 220, 221, 222 on their respective rack wagons 206,206′, 206″ can be varied to move elements of the device at the distalend of the 24 French 224, for example sliding of the proximal rack wagon206″ may advance the papillary anchor 9 and thereby implant it into thepapillary muscle.

To indicate the amount of tension and/or deflection applied to eachpullwire controlled by the gears and/or dials 226 a, 226 b, 226 c of thecatheter device, a number of indicators 227 a, 227 b, 227 c may also bedisposed on an outer surface of the operating handle 220. These may beused as feedback indicators to indicate to the operator of the catheterdevice 2 how much tension is currently applied to the pullwires, alongwith their current behaviour/positioning. The indicators 227 a, 227 b,227 c may be used in addition to and/or alternatively to the variousclutch configurations discussed above.

Whilst the functionality of the operating handle has only been discussedin relation to a single operating handle 220, it will be readilyunderstood that some or all of the features discussed herein may beapplied to the other operating handles 221, 222 of the delivery handle200.

FIGS. 52A and 52B show the main body of the catheter device 2. The mainbody comprises a proximal part 4 and a distal part 8, the two partsconnected to one another at the hinge element 104. The distal part 4 mayhouse the papillary anchor 9 as discussed above and as shown in theprevious Figures. The hinge element 104 may operate as discussed abovewith reference to the flexible joint and as shown in the previousFigures. A guide wire 1 runs through the catheter device 2 and extendsout of the distal part 8. The main body of the catheter device 2 may beformed of a composite material, for example glass reinforced PEEK, orcarbon reinforced PEEK. The proximal part 4 of the catheter device 2 maybe joined to a steerable catheter of the catheter device 2 by reflowingpolymer at the location of the joint.

Focusing on the proximal part 4 of the catheter device 2, the mechanicalgripper device 6 may be seen. The mechanical gripper device 6 comprisesa first gripper arm 30 and a second gripper arm 32, with the mechanicalgripper device 6 being in accordance with one of the embodimentspreviously discussed. FIG. 52A shows the first gripper arm 30 and thesecond gripper arm 32 moved away from a main body of the catheter device2. The mechanical gripper device 6 may be configured such that the firstgripper arm 30 moves to meet the second gripper arm 32. The firstgripper arm 30 may be moved until a contact is made between the two arms30, 32. With the second gripper arm 32 configured to be placed on top ofa leaflet 10 to suppress its motion, the first gripper arm 30 may thenbe rotatably moved back in to the proximal part 4 of the main body ofthe catheter device 2. As it does so, the first gripper arm 30 is ableto grasp the restrained leaflet 10 between itself and the main body ofthe catheter device 2. The leaflet anchor 10 may be housed within thefirst gripper arm 30 in accordance with any of the embodiments discussedabove.

As shown in FIGS. 52A and 52B, the second gripper arm 32 may be aleaflet motion suppressor 32 comprising a loop of wire. The wire may bemade of a suitably elastic material, for example nitinol or stainlesssteel. Thus, when the leaflet motion suppressor 32 is not housed withinthe main body of the catheter device 2, it is in an undeformed state.The elasticity of the leaflet motion suppressor 32 allows the leafletmotion suppressor 32 to suppress the motion of the leaflet 10 during acardiac cycle, whilst allowing the first gripper arm 30 to contact theleaflet motion suppressor 32 without damaging the leaflet 10 restrainedbetween the two arms 30, 32. The elasticity of the leaflet motionsuppressor 32 allows the leaflet motion suppressor 32 to curve as shownin FIG. 52B when it comes into contact with the first gripper arm 30,thus helping to avoid any pinching of the leaflet 10 which may result indamage of the leaflet 10 as it is restrained.

The leaflet motion suppressor 32 may be housed within a lumen (notshown) of the catheter device 2. When housed within the lumen, theleaflet motion suppressor 32 comprises an elastically deformed state.The lumen may run parallel to a main axis of the catheter device 2,before angling to meet a surface of the proximal part 4 proximal thelocation of the mechanical gripper device 6. The lumen may be angledsuch that the leaflet motion suppressor is angled as shown in FIGS. 52Aand 52B.

The loop formed in the loop of wire may prevent the leaflet motionsuppressor 32 from being fully withdrawn into the catheter device 2. Forexample, the end of the lumen may feature a pin extending across anopening of the lumen, located at the surface of the proximal part 4. Theloop of the wire may engage the pin when it is slidably moved into thecatheter device, thus preventing the leaflet motion suppressor 32 frombeing withdrawn any further into the catheter device 2. The loop of thewire may therefore move from a location flush with the outside surfaceof the proximal part 4 to a position away from the main body of thecatheter device 2, as shown in FIGS. 52A and 52B.

FIGS. 53A, 53B and 53C show the leaflet motion suppressor 32 engagingwith a leaflet 12 of a model mitral valve at various stages of itsoperation. For example, the catheter device 2 may approach the mitralvalve from a top-down approach (i.e. from the left atrium into the leftventricle). As shown in FIG. 53A, the leaflet motion suppressor 32 isslid out of its lumen, engaging with a top surface of the leaflet 12.The loop extends over a suitably large distance such that there issufficient contact between the leaflet 12 and the leaflet motionsuppressor 32. The first gripper arm 30 remains closed. The catheterdevice 2 is then moved down through the mitral valve before the firstgripper arm 20 is rotated outwards, away from the main body of thecatheter device 2, as shown in FIG. 53B. Finally, the first gripper arm30 may be moved towards the leaflet motion suppressor 32, such that theleaflet 12 is firmly restrained by the mechanical gripper device 6 via acontact force between the leaflet motion suppressor 32 and the firstgripper arm 30. The contact may be a slidable contact, such that thefirst gripper arm 30 may then rotate back towards the main body of thecatheter device 2 with the leaflet 10 still being restrained, before theleaflet is then grasped between the first gripper arm 30 and the mainbody of the catheter device 2, in the mechanical gripper device 6. Theleaflet anchor 10 (as in the prior Figures) may then be deployed andimplanted in the leaflet 12, with the motion of the leaflet 12suppressed during the gripping motion.

Whilst FIGS. 53A, 53B and 53C show the leaflet motion suppressor 32comprising a loop of wire, the leaflet motion suppressor 32 may comprisea number of shapes and/or arrangements to achieve its objectivefunction. For example, FIGS. 54A, 54B and 54C show an alternativeembodiment of the leaflet motion suppressor 32′ comprising an open-endedpiece of wire, an end of the wire being located outside of the main bodyof the catheter device 2. The over-arching principle of the leafletmotion suppressor 32′ shown in FIGS. 54A, 54B and 54C is aligned withthat of the leaflet motion suppressor 32 as shown in FIGS. 53A, 54B and54C respectively, as described above.

To prevent the leaflet motion suppressor 32′ comprising a single pieceof wire from being completely withdrawn into the catheter device 2 as itis slidably moved back into the lumen which houses it, a wire stopper(not shown) may be disposed at the end of the wire located outside themain body of the catheter device 2. It will be appreciated that the wirestopper will need to be of a shape suitably larger than the openingformed by the lumen, such that the wire stopper is incapable of beinghoused within the lumen.

As the leaflet motion suppressor 32′ is withdrawn into the lumen, theleaflet motion suppressor 32′ will elastically deform from itsundeformed state to its elastically deformed state. For example, thewire may straighten and may comprise the shape of the lumen it is housedwithin.

The leaflet motion suppressor 32′ shown in FIGS. 54A, 54B and 54Ccomprises a spiral shape towards the end of the wire. The spiral shapeprovides a larger surface area for engagement with the leaflet 12.Additionally, the end of the wire may be located at the centre of thespiral shape. This encloses the end of the wire, such that it is lesslikely that the end of the wire may pierce and/or damage the tissue thatit contacts. The spiral shape may be described as a pig-tail shape. Whena constraining force is applied (i.e. by the internal walls of thelumen), the wire may straighten but when the constraining force isremoved (i.e. the wire is moved out of the lumen, the end of the wiremoving away from the main body of the catheter device), the wire maycoil into the spiral shape shown in the Figures.

FIGS. 55A, 55B and 55C show alternative arrangements for the leafletmotion suppressor 32′, each arrangement capable of being implementedsimilarly to the examples discussed above. As shown in the Figures, theleaflet motion suppressor 32′ may comprise a number of bends and/orcurves which increase its effective surface area of engagement with theleaflet 12. In its undeformed state the piece of wire displays the bendsand/or curves it is formed with. However, when withdrawn into the lumen,it will be understood that the elastic wire deforms and straightens out,taking on a shape which complements the structure of the lumen. Theleaflet motion suppressor 32′ comprising an open-ended wire, as shown inFIGS. 54A to 55C may comprise a soft tip at the end of the wire todecrease the likelihood of the wire piercing and/or damaging thesurrounding tissue, such as the leaflet 12.

The wire component of the leaflet motion suppressor 32, 32′ may be anoff-the shelf wire, such as a guide wire, readily available for use incardiac interventions. Accordingly, an operator of the catheter device 2can then choose a wire that they find appropriate for suppressing motionof the leaflet 12 during an operation. In other words, different wiresof an identical predefined size may be implemented with differentstiffness and/or tip structure (i.e. bends, curves and/or loops) asdesired. For example, if a first wire did not function as desired, asecond wire having similar or different characteristics may be used. Assuch, the leaflet motion suppressor 32, 32′ may not be stored within thelumen of the catheter device 2, but may be selected from a storagedevice and inserted into a port of the catheter device 2 during aparticularly challenging insertion of a leaflet anchor 10 into a leaflet12.

1. An anchor for implantation in body tissue to hold a line, the anchorcomprising a number of hooks for engagement with the body tissue andhaving a folded position and an unfolded position, wherein the anchor ismade of an elastic material such that it can be elastically deformedinto the folded position by application of a constraining force, andwill return to the unfolded position when no constraining force isapplied, and wherein the hooks are formed with openings along theirlength, wherein the openings in the hooks comprise slits extending alongsome or all of the length of the hooks.
 2. An anchor as claimed in claim1, wherein the slits are be extended beyond the ends of the hooks wherethey join into the base of the anchor.
 3. An anchor as claimed in claim1 or 2, wherein the openings in the hooks include multiple holes, withthese holes being connected with a suture; and wherein a single lengthof suture passes through several of the multiple holes.
 4. An anchor asclaimed in claim 1, 2 or 3, wherein the openings include severalseparate slits in line along the length of the hooks.
 5. An anchor asclaimed in any preceding claim, wherein the anchor is formed from a tubethat has been cut to provide tines extending from one end of the tube,with these tines then having been curved and heat set to form the hooks.6. An anchor as claimed in any preceding claim, wherein the anchorincludes a locking mechanism arranged to clamp a line when no force isapplied to the locking mechanism.
 7. An anchor as claimed in claim 6,wherein the locking mechanism comprises a locking ring that is able tobe elastically deformed to release the line from the locking mechanismfor adjustment of the length of the line.
 8. A catheter device forimplanting an artificial chordae line into the body, the catheter devicecomprising an anchor as claimed in any preceding claim with the anchorbeing a leaflet anchor or a papillary anchor.
 9. A catheter device asclaimed in claim 8, wherein the anchor is a papillary anchor including alocking mechanism with a locking ring; and the catheter device comprisesa papillary anchor deployment mechanism having a locking ring holder forholding the locking ring in its elastically deformed position, with thepapillary anchor deployment mechanism being arranged to selectivelywithdraw the locking ring holder from the locking ring so that thechordae line can be locked in place after deployment of the papillaryanchor and after any required adjustment of the length of the chordaeline.
 10. A catheter device as claimed in claim 9, wherein the lockingring holder is a Z-shaped fork.
 11. A catheter device as claimed inclaim 8, 9 or 10 comprising: a two-part housing section extending from adistal end of the catheter device along the length of the catheterdevice toward the proximal end of the catheter device, the two-parthousing section being arranged to be placed between the papillary muscleand a leaflet of the heart during use of the catheter device, and thetwo-part housing section comprising a distal part at the distal end ofthe catheter device and a proximal part located on the proximal side ofthe distal part; a leaflet anchor deployment mechanism at the proximalpart of the housing section for deploying a leaflet anchor forattachment to the leaflet of the heart; a papillary anchor deploymentmechanism at the distal part of the housing section for deployment of apapillary anchor for attachment to the papillary muscle, wherein thepapillary anchor deployment mechanism is arranged for deployment of thepapillary anchor by moving it outward in the distal direction relativeto the distal part; and a flexible joint located between the proximalpart and the distal part of the two-part housing section, wherein theflexible joint allows a centreline of the distal part to be angledrelative to a centreline of the proximal part; wherein the leafletanchor and/or the papillary anchor are anchors as claimed in any ofclaims 1 to
 7. 12. A catheter device as claimed in any of claims 8 to10, including a leaflet anchor being an anchor as claimed in any ofclaims 1 to 7, and comprising a leaflet anchor deployment mechanism thatallows for retraction and repositioning of the leaflet anchor afterdeployment of the anchor into the leaflet via an ejector unit having agrasping device with a first configuration arranged to permit deploymentof the leaflet anchor into the leaflet without disengagement of theleaflet anchor from the ejector unit, and a second configuration inwhich the leaflet anchor is reversibly released from the ejector unit;wherein in the first configuration the grasping device of the ejectorunit grasps a proximal end of the leaflet anchor, whilst a distal end ofthe leaflet anchor is unimpeded by the grasping device to enable it tobe implanted in the leaflet; and wherein in the second configuration thegrasping device of the ejector unit is disengaged from the leafletanchor.
 13. A catheter device as claimed in any of claims 8 to 10,including a leaflet anchor being an anchor as claimed in any of claims 1to 7, and comprising a leaflet anchor deployment mechanism thatcomprises a mechanical gripper device for grasping the leaflet of theheart valve, wherein the gripper device comprises a leaflet anchor tubefor housing the leaflet anchor in a folded configuration; the gripperdevice and leaflet anchor being arranged such that when, in use, thegripper device grasps the leaflet, the leaflet anchor can be pushed outof the leaflet anchor tube to pierce the leaflet and form the leafletanchor into an unfolded configuration so that hooked formations of theleaflet anchor can, in use, secure the leaflet anchor in the leaflet;wherein the mechanical gripper device includes a first gripper armrotatably coupled to a main body of the catheter device so that thefirst gripper arm can rotate relative to the catheter device to move anouter end of the first gripper arm away from the main body of thecatheter device and a second gripper arm rotatably and/or slideablycoupled to the main body of the catheter device so that the secondgripper arm can rotate and/or slide relative to the main body of thecatheter device to move an outer end of the second gripper arm away fromthe main body of the catheter device; and wherein the first and secondgripper arms are arranged so that they can move to come into contactwith one another at a point spaced apart from the main body of thecatheter device.
 14. A catheter device as claimed in any of claim 11, 12or 13, wherein the leaflet anchor can be pushed out of the leafletanchor deployment mechanism in a direction extending from the distal endof the catheter device toward the proximal end of the catheter device.15. A catheter device as claimed in any of claims 8 to 14, comprising aU-shaped rod for deployment of the leaflet anchor.
 16. A method of useof the anchor of any of claims 1 to 7 for affixing an artificial chordaeline to the heart, the method comprising using an anchor deploymentdevice to implant the anchor into the tissue of the heart.
 17. A methodof manufacture of an anchor as claimed in any of claims 1 to 7, themethod comprising: forming tines into an elastic metal tube via cutting;forming openings in the tines; and deforming the tines into hooked formsand heat setting them to form the hooks with openings.
 18. A method asclaimed in claim 17, wherein the elastic metal tube is a nitinol tube.19. A method as claimed in claim 17 or 18, wherein the cutting step isdone using laser cutting.
 20. A method as claimed in claim 17, 18 or 19,wherein the tube is electropolished after cutting in order to remove anysharp edges.
 21. A method as claimed in any of claims 17 to 20 whereinthe openings are cut into the tines before they are deformed and heatset.
 22. A method as claimed in any of claims 17 to 21, wherein theopenings include slits and the slits are laser cut as a single lasertrack.
 23. A method as claimed in claim 22, wherein circular openingsare added to the ends of the single laser track slits.